Hi Team,
I am unable to load the Cesium World Terrain + Bing Maps Aerial in Unreal Engine from yesterday(16- 09-2025).
Getting the below error
LogCesium: Error: [2025-09-17 13:01:19.151] [error] [ErrorList.h:89] Errors while loading image for tile: Received response code 401 for image https://assets.ion.cesium.com/proxy/2/t1/3?access_token=
The most common cause of CWT + Bing suddenty not working, accompanied by a 401 error, is that you were using the default Cesium ion key included in the Samples project. We periodically revoke those in order to discourage abuse. You should create your own Cesium ion account and access token for use in your project.
If thatâs not it, please let me know.
Hi @Kevin_Ring ,
I am using my own Cesium Ion account and accessing it with my access token. However, I am still getting the same error.
Please note that this error has been occurring since yesterday (16-09-2025).
We have the same issue with the Bing Maps Aerial with labels dataset not loading. OpenStreetMaps and our own data is loading.
It worked for us yesterday, about 24 h ago.
Hey ! I have the same problem since yesterday please help.
The problem for me at least seem to be with Unreal Engine 5.1, where the project is built.
I tried making a test project in Unreal Engine 5.5, and Bing Aerial with Labels work there.
But it doesnât work for a test project in Unreal Engine 5.1
Iâm also having this trouble, using Cesium for Unreal. This happened once before, but was a transient error that we never got to the root cause of.
One thing I see but donât understand is that the 401 error URL has an access token that differs from the project token. The upshot is that âTroubleshoot tokenâ shows all-clear, but the imagery does not load. Does the Ion client use its own token for Bing?
Error token: eyJhbâŚ1XvIk
Project token: eyJhbâŚZlISo
n.b. Other imagery, e.g. Blue Marble works fine
I was using Cesium for Unreal 2.17. Upgrading to 2.19 fixed the problem.
We were getting the same error as well, both yesterday and early this morning. We issued new tokens, no dice. Issue appeared to resolve itself on the Cesium Ion side without us doing anything. Seems like an outage.
Yupp same as me this was working monday bugt now it is not, unreal 5.2 it would be a shame to have to recompile and relaunch our project to all the users to fix this.
LogHttp: Warning: 000008089423F000: invalid HTTP response code received. URL: https://assets.ion.cesium.com/proxy/3/t3/210302?access_token
I reinstalled the latest plugin, but it still cannot read the map. It seems the update had no effect.
Hi @Kevin_Ring ,
Could you please provide a resolution for this as a priority matter, since it is blocking further progress for me.
Thank you.
Hi everyone, sorry to hear about all the problems with Bing Maps. There was a Bing Maps outage yesterday that was probably the cause of most of these issues. Please retry today and see if youâre still having trouble.
If youâre having trouble with some other tileset, and youâve already checked that a) your Cesium ion token is valid, and b) your token is configured to allow access to the particular tileset youâre trying to use, then please start a new thread with as much information as possible about the problem and we will take a look.
