# Download of CityGML 3dtiles validator shows multiple Errors

**URL:** <https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502>\
**Category:** Cesium ion\
**Created:** [March 13, 2026, 7:55am UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502 "2026-03-13T07:55:26Z")\
**Posts on this page:** 20\
**Page:** 1

<div class="post-metadata">

**Author:** ![esg](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/esg/32/14000_2.png) [@esg](https://community.cesium.com/u/esg)\
**Post date:** [March 13, 2026, 7:55am UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/1 "2026-03-13T07:55:26Z")

</div>

Hi,

I uploaded CityGML - no error shown - and would like to download it from ION.

Due to problems in showing the content, i checked the files with the 3d-tiles-validator.

I got hundreds of errors - from CONTENT\_VALIDATION\_ERROR, CONTENT\_JSON\_INVALID, BINARY\_INVALID\_ALIGNMENT, …

Does this mean, that Cesium ion could not produce a valid 3d-tiles file ?

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<div class="post-metadata">

**Author:** ![mdc9001](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/mdc9001/32/15919_2.png) [@mdc9001](https://community.cesium.com/u/mdc9001)\
**Post date:** [March 13, 2026, 5:55pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/2 "2026-03-13T17:55:19Z")

</div>

Hi esg,

Can you let us know what asset id this was for so we can investigate the issue further?

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<div class="post-metadata">

**Author:** ![esg](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/esg/32/14000_2.png) [@esg](https://community.cesium.com/u/esg)\
**Post date:** [March 14, 2026, 5:26pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/3 "2026-03-14T17:26:01Z")

</div>

Hi Mark,

it is AssetId 4522606 – i have download the tiles[Download LoD2-DE\_HH\_2025-03-14\_ogc.zip](https://api.cesium.com/v1/archives/274338/download)uncompress it and checked it with 3dtiles-validator

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<div class="post-metadata">

**Author:** ![mdc9001](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/mdc9001/32/15919_2.png) [@mdc9001](https://community.cesium.com/u/mdc9001)\
**Post date:** [March 16, 2026, 3:08pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/5 "2026-03-16T15:08:14Z")

</div>

Thanks for sharing that information. I was able to confirm that it did show errors for me as well. I have reached out to other members of our team who are more familar with the 3D tiles validator and CityGML tiling to see if they have any insights.

Are you having any issues viewing the data or is it just the validation messages you are concerned about?

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<div class="post-metadata">

**Author:** ![esg](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/esg/32/14000_2.png) [@esg](https://community.cesium.com/u/esg)\
**Post date:** [March 16, 2026, 4:34pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/6 "2026-03-16T16:34:33Z")

</div>

Hallo Mark,

yes I had a lot problems to display the CityGML - i use on one side Cesium 1.92 and I see only 3-4 buildings of the whole town. so I wondered if it depends on the values of screenspace-error or if there are data inside the 3d-tiles. Using this dataset in a sandcastle everything looks fine !

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<div class="post-metadata">

**Author:** ![esg](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/esg/32/14000_2.png) [@esg](https://community.cesium.com/u/esg)\
**Post date:** [March 16, 2026, 5:10pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/7 "2026-03-16T17:10:37Z")

</div>

![Cesium_SandcastleAdjustHeightCesiumIon1.139](https://global.discourse-cdn.com/cesium/original/3X/1/d/1d30f5afb466960894473b983418257da9e4d767.jpeg)

 ![Cesium_SandcastleAdjustHeightCesiumIon1.65](https://global.discourse-cdn.com/cesium/original/3X/0/7/07730a0ffa1cda5bcd006e14e6903ab53214bb4c.jpeg)

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<div class="post-metadata">

**Author:** ![Marco13](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/marco13/32/2757_2.png) [@Marco13](https://community.cesium.com/u/Marco13)\
**Post date:** [March 16, 2026, 6:39pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/8 "2026-03-16T18:39:20Z")

</div>

The CesiumJS version in the second screenshot is 1.65, and this is more than 5 years old. One can see that there _are_ several buildings, but they are all displayed at only two different places. It’s difficult to pinpoint the reason for that (maybe there is some error message in the developer console that should appear when you press F12), but I’d say that one can simply not expect such an old version to still be able to process more recently created data sets.

(Note that this is entirely different than the opposite direction: Data that was created 5 years ago should (and generally does) work in the most recent CesiumJS version. But _new_ data may include some new features that are simply not supported by old CesiumJS versions)

But… all that is unrelated to the 3D Tiles Validator issues. When a newly created data set is not valid and generates validator errors, then that’s an issue and has to be investigated further.

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<div class="post-metadata">

**Author:** ![esg](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/esg/32/14000_2.png) [@esg](https://community.cesium.com/u/esg)\
**Post date:** [March 17, 2026, 7:27am UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/9 "2026-03-17T07:27:10Z")

</div>

Hi Marco,

sorry I disagree - also Cesium 1.65 was able to display Cesium 3DTiles of format 1.0 !!

That is a question of which format is delivered, not which viewer is used - in my opinion !!

There aren’t any errors on the console in the old viewer !

In the 1.91 i see single buildings but not more !

 ![image](https://global.discourse-cdn.com/cesium/original/3X/6/d/6db74b2ab826a42c680e5070dc950fef1e9a9ee9.jpeg)

That is only sandcastle - no code from me !

---

<div class="post-metadata">

**Author:** ![Marco13](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/marco13/32/2757_2.png) [@Marco13](https://community.cesium.com/u/Marco13)\
**Post date:** [March 17, 2026, 1:45pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/10 "2026-03-17T13:45:50Z")

</div>

There seem to be different CesiumJS version numbers involved:

- 1.139.1 in the first screenshot. This seems to work
- 1.65 in the second screenshot. There, all buildings appear to be in just two locations. (These “blocks” that can be seen there are not single buildings - they look like _many_ buildings that are displayed in these two places)
- 1.91 (or 1.92 mentioned in a comment), which may have been used in the last screenshot. In that last screenshot, I don’t see any buildings at - only the bounding volumes. But maybe the buildings are all displayed at wrong place, similar to the second screenshot

Is there a _specific_ (older) version of CesiumJS that you would like to use? (Or conversely: Is it not possible to just update to the latest version, 1.139, which _seems_ to work properly?)

> also Cesium 1.65 was able to display Cesium 3DTiles of format 1.0 !!
> 
> That is a question of which format is delivered, not which viewer is used - in my opinion !!

That’s correct. I don’t know (from the tip of my head) which tileset version the GML tiler is currently generating. But if it is generating 3D Tiles 1.0, then it should indeed work in older CesiumJS versions as well.

With one small caveat: Maybe there was some sort of bug in one of these older CesiumJS versions that was fixed in the meantime. That’s hard to say for sure. But when the same tileset is not displayed propery in 1.65 **and** 1.91, then this would mean that this bug was not fixed between these versions, and that’s unlikely.

In any case (regardless of the CesiumJS version and why exactly things are not working in certain versionss), there is something wrong with the data, given that the 3D Tiles Validator declares this tileset as ‘invalid’. (Which of these validation errors could be the _reason_ for the rendering issues remains to be investigated).

I hope that someone from the Cesium ion / tilers team can have a closer look at this asset (with asset ID 4522606 as you mentioned), to see what could be wrong there.

**If** the downloaded tileset is ~“not too large”, and if it can be shared (maybe as a private message), then I might have a closer look at the tileset and the validator report. This could just be a first investigation. I could probably not fix the issue at the source, in the GML tiler. But maybe I can find out what exactly is wrong and why it is not displayed properly in older CesiumJS versions.

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<div class="post-metadata">

**Author:** ![esg](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/esg/32/14000_2.png) [@esg](https://community.cesium.com/u/esg)\
**Post date:** [March 17, 2026, 2:08pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/11 "2026-03-17T14:08:53Z")

</div>

Hi Marco,

sorry, to clear the situation:

 ![image](https://global.discourse-cdn.com/cesium/original/3X/2/8/28145e420f02878c14a1b08f83c5377c7f3aa3cb.jpeg)

We have a bigger application at our customer based on Cesium 1.91. The customer has problems to deliver the necessary data. The customer would like to use Cesium Ion Self hosted and tested the data with Cesium ion. The customer loaded the dataset, i used.

In the examples:

I used the 1.65, because I could reproduce a difference, very fast. This morning I do a new installation with npm install of the 1.91 and use the sandcastle to reproduce the behaviour of my application. The behaviour is, that I only see single buildings - like in my application.

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<div class="post-metadata">

**Author:** ![esg](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/esg/32/14000_2.png) [@esg](https://community.cesium.com/u/esg)\
**Post date:** [March 17, 2026, 2:17pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/12 "2026-03-17T14:17:09Z")

</div>

I use the following code:

```auto
Cesium.Ion.defaultAccessToken ="XXX";

var viewer = new Cesium.Viewer('cesiumContainer', {
    terrain: Cesium.createWorldTerrain(),
    // shadows : true
});

viewer.scene.globe.depthTestAgainstTerrain = true;
//Add Cesium Inspector
viewer.extend(Cesium.viewerCesiumInspectorMixin);
$('.cesium-viewer-cesiumInspectorContainer').css('visibility', 'visible');

var tileset = new Cesium.Cesium3DTileset({
    url: Cesium.IonResource.fromAssetId(4522606),
});

tileset.readyPromise.then(function(tileset) {
    viewer.scene.primitives.add(tileset);
    viewer.zoomTo(tileset, new Cesium.HeadingPitchRange(0.0, -0.5, tileset.boundingSphere.radius * 2.0));
}).otherwise(function(error) {
    console.log(error);
});

```

The data is in Hamburg

 ![image](https://global.discourse-cdn.com/cesium/original/3X/c/7/c70ed015209bf31678c36a3b7bab34c223babfcc.jpeg)

I could look at the building and send the CityGML of that region !

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<div class="post-metadata">

**Author:** ![esg](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/esg/32/14000_2.png) [@esg](https://community.cesium.com/u/esg)\
**Post date:** [March 17, 2026, 2:48pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/13 "2026-03-17T14:48:56Z")

</div>

I have uploaded a smaller Dataset in Cesium ion 4538441, only one file

I could also send you the xml - private

 ![image](https://global.discourse-cdn.com/cesium/original/3X/0/1/01cff6f82e8d1ae441a980cbf6547539b80a3b06.jpeg)

Maybe there is a problem in ion - I chose the texture option and clamptoground to the Cesium World terrain.

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<div class="post-metadata">

**Author:** ![Marco13](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/marco13/32/2757_2.png) [@Marco13](https://community.cesium.com/u/Marco13)\
**Post date:** [March 17, 2026, 4:01pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/14 "2026-03-17T16:01:41Z")

</div>

Maybe someone from [@cesium-tilers](https://community.cesium.com/groups/cesium-tilers) can have a closer look at …

- the original asset, 4522606
- the new, smaller asset, 4538441

and see whether anything stands out. If you send me the downloaded tileset of the smaller one (as a private message) then I can also have a look, but cannot promise anything - if there is a bug, then it will likely have to be fixed in the GML tiler.

---

<div class="post-metadata">

**Author:** ![esg](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/esg/32/14000_2.png) [@esg](https://community.cesium.com/u/esg)\
**Post date:** [March 17, 2026, 4:36pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/15 "2026-03-17T16:36:53Z")

</div>

Hi Marco,

i have put the original xml und the 3d-Tiles Files.

Ihave produced a even smaller one only 3 buildings !

[LoD2\_HH\_test.zip](https://community.cesium.com/uploads/short-url/gNf8Y21leudSIBeO4v3dzIhTwqO.zip) (3.1 KB)

[LoD2\_32\_574\_5922\_1\_HH.zip](https://community.cesium.com/uploads/short-url/ovrkcNRcw5blepEupUyg8GXW7mW.zip) (163.4 KB)

_(Edit: Removed one file based on user request)_

> [@Download of CityGML 3dtiles validator shows multiple Errors](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/14):
>
> Maybe someone from [@cesium-tilers](https://community.cesium.com/groups/cesium-tilers) can have a closer look at … the original asset, 4522606 the new, smaller asset, 4538441 and see whether anything stands out. If you send me the downloaded tileset of the smaller one (as a private message) then I can also have a look, but cannot promise anything - if there is a bug, then it will likely have to be fixed in the GML tiler.

---

<div class="post-metadata">

**Author:** ![esg](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/esg/32/14000_2.png) [@esg](https://community.cesium.com/u/esg)\
**Post date:** [March 17, 2026, 5:02pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/16 "2026-03-17T17:02:22Z")

</div>

Hi Marco,

Itested the very small Dataset with the 3 Buildings - I only see one Building

 ![image](https://global.discourse-cdn.com/cesium/original/3X/f/2/f25584f5781d94265e2c8da07b83c58afca20e50.png)

 ![image](https://global.discourse-cdn.com/cesium/original/3X/e/d/ed4158325c689fc494f35a3061c143594df93dc7.jpeg)

---

<div class="post-metadata">

**Author:** ![esg](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/esg/32/14000_2.png) [@esg](https://community.cesium.com/u/esg)\
**Post date:** [March 19, 2026, 12:29pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/17 "2026-03-19T12:29:59Z")

</div>

Any NEWS ?

---

<div class="post-metadata">

**Author:** ![Marco13](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/marco13/32/2757_2.png) [@Marco13](https://community.cesium.com/u/Marco13)\
**Post date:** [March 19, 2026, 1:44pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/18 "2026-03-19T13:44:07Z")

</div>

Juggling priorities…

However, I had another look. The validation errors (just to keep track of that) are of two forms. Several errors are

```auto
{
  "type": "BINARY_INVALID_ALIGNMENT",
  "path": "1/1/1.b3dm",
  "message": "The byte length must be aligned to 8 bytes",
  "severity": "ERROR"
},

```

That’s clearly invalid. It’s not a “critical” error, insofar that _many_ tools will not rely on the alignment. But any specification-compliant tool _could_ rely on the alignment, and it _could_ crash, so that should simply be fixed. It is already tracked internally, but I don’t know when this will be addressed.

There is one other error:

```auto
{
  "type": "CONTENT_JSON_INVALID",
  "path": "1/1/0.b3dm",
  "message": "Batch table property \"gml:name\" array length must equal features length 161.",
  "severity": "ERROR"
}

```

That’s also invalid. It might also cause crashes in other applications. I think that it is not tracked _explicitly_, and I haven’t investigated the details. I’ll just add it to the internal issue for now.

* * *

That said: We had some discussion about ‘versions’ above:

> > > But _new_ data may include some new features that are simply not supported by old CesiumJS versions
> > 
> > That is a question of which format is delivered, not which viewer is used - in my opinion !!
> 
> That’s correct. I don’t know (from the tip of my head) which tileset version the GML tiler is currently generating. But if it is generating 3D Tiles 1.0, then it should indeed work in older CesiumJS versions as well.

One thing that was **not** taken into account in this discussion is that of the _tile content_. Specifically: glTF (`.glb` files). And even more specifically: Which _extensions_ this glTF contains, and which of them are supported in the client. And to come to the point: Whether the client supports the `KHR_draco_mesh_compression` extension. By default, GML is tiled into Draco-compressed data (and KTX textures, if applicable). Older versions of CesiumJS may not support this.

When upploading your data, you should disable KTX and Draco compression:

![Cesium Forum GML validation](https://global.discourse-cdn.com/cesium/original/3X/c/f/cf0488bfd265ba7bed43fe26940a864d1537065d.gif)

The result should be a data set like this one:

[Forum 45502 - GML Errors - LoD2\_32\_574\_5922\_1\_HH.zip](https://community.cesium.com/uploads/short-url/56ScVU6yqvxxfdqSw45ZMA3XD9V.zip) (426.4 KB)

This can be loaded in CesiumJS 1.91 with a Sandcastle like this one:

```javascript
const viewer = new Cesium.Viewer("cesiumContainer", {
  globe: false
});

function loadTileset() {
  const tileset = new Cesium.Cesium3DTileset(
    {
      url: "http://localhost:8003/tileset.json",
      debugShowBoundingVolume: true,
    }
  );
  viewer.scene.primitives.add(tileset);
  const offset = new Cesium.HeadingPitchRange(
    Cesium.Math.toRadians(-45.0),
    Cesium.Math.toRadians(-45.0),
    2800.0
  );
  viewer.zoomTo(tileset, offset);
}

loadTileset();

```

The result should then look like this:

 ![Cesium Forum GML validation](https://global.discourse-cdn.com/cesium/original/3X/f/8/f843f29971c481449f0bcfc0cceb1dfdf9190074.jpeg)

Let me know if anything doesn’t work.

---

<div class="post-metadata">

**Author:** ![esg](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/esg/32/14000_2.png) [@esg](https://community.cesium.com/u/esg)\
**Post date:** [March 23, 2026, 12:31pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/19 "2026-03-23T12:31:28Z")

</div>

Hi Marco,

I saw your message today - I tested also and my result is, that the ClampToGround is the problem !

I tested my small dataset and set no draco, no texture and no coordinates !

–\> Result everything is fine in Cesium 1.91

–\> but you could only use the dataset with wgs84 ellipsoid

if I set clamptoground with Cesium WorldTerrain

–\> I got wrong results

–\> Could the EPSG:25832 be a problem for the clampToground

---

<div class="post-metadata">

**Author:** ![esg](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/esg/32/14000_2.png) [@esg](https://community.cesium.com/u/esg)\
**Post date:** [March 23, 2026, 1:01pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/20 "2026-03-23T13:01:51Z")

</div>

Hi Marco,

I have now made more tests - and definitely from my opinion it is the clamptoground parameter

I also produced a file with converted coordinates to EPSG:4326 and this doesn’t changed anything

```auto
                              wgs84 ellipsoid cesium world terrain      

```

EPSG:4326 in CityGML fine under surface

EPSG:4326 clamp to world terrain fine under surface

So question:

What EPSG could be used that Cesium ion produces data (with the clamp to ground option) which could be viewed with Cesium 1.91

I used the [Converting to/from CityGML files | CityJSON](https://www.cityjson.org/tutorials/conversion/) to convert the CityGML from one srs to another !

Rüdiger

WGS84 ellipsoid:

 ![image](https://global.discourse-cdn.com/cesium/original/3X/e/0/e08770ef529bad97ba9ea4b4b167c186a50f83df.jpeg)

Cesium World Terrain, buildings lie under the surface allthough clamptoground is used !

 ![image](https://global.discourse-cdn.com/cesium/original/3X/d/9/d9e052c03c43d1dadf8b18c3372572dfbb4c17d0.jpeg)

---

<div class="post-metadata">

**Author:** ![Marco13](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/marco13/32/2757_2.png) [@Marco13](https://community.cesium.com/u/Marco13)\
**Post date:** [March 23, 2026, 8:29pm UTC](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502/21 "2026-03-23T20:29:35Z")

</div>

I don’t have particular expertise in that area. Maybe [@cesium-ion](https://community.cesium.com/groups/cesium-ion) : Are there any known constraints or limitations when it comes to GML and clamping it to CWT?

[Next page](https://community.cesium.com/t/download-of-citygml-3dtiles-validator-shows-multiple-errors/45502.md?page=2)