I am getting TypeError: Cannot read property '_definitionChanged' of undefined

I have a working example of cesium where I show some 3D models and update it with some actions of the user, this is working with 1.24 version of cesium, but after updating cesium to 1.44 I am getting this error with the same code

I am getting TypeError: Cannot read property ‘_definitionChanged’ of undefined

This is the code this function has, where the error goes, but I don’t call it directly, as I said, this code is working with 1.24 version

Another thing is that I am getting too much crashes of browser without console errors, can this be the problem? like a silent error with the other version of cesium? thanks

I am testing it in linux mint, with chrome

Hi Humberto,

Upgrading from Cesium 1.24 to 1.44 will likely break quite a few things, take a look at CHANGES.md for the full list of changes.

Is this your code, or a snippet of Cesium source code? If possible, providing a code snippet, maybe one with Sandcastle, will help track down the source of the error.

I’m not sure about your silent crashes, I don’t think there’s enough info here to track down what’s causing those.



Dear Gabby,

Thank you for your post. I am working with Humberto and your post is helpful to know about all the Cesium updates we have now incorporated. The new Cesium version uses new objects for constants values that the Jquery ajax call was unable to understand, so we added a getValue() call on those values that were supposed to be constants.

For some reason we continue to have browser crashes from time to time and there is no way to detect this in the ‘console.’ As Humberto requests below, “are there debugging tools for Cesium that we can use to detect these errors?”

Thank you,


The browser debugger should work. For example, if you are using chrome, click the menu, then select “More Tools” > “Developer Tools”.