After Update to MODX3 Unexpected token '<'


I have to Update several MODX2.8.4. installations. I did the first update - still after several attemps, I always get that error in the browser console:
Uncaught SyntaxError: Unexpected token '<'

The resource list in the manager does not load, caused by that error.

I cleared the cache and checked several settings.

Does anyone have an idea how to fix it?

Kind regards

It looks like a processor in the manager returns HTML instead of JSON.

Can you open the developer tools in the browser, go to the “Network” tab and then check what request exactly returns the unexpected result? It probably has the action parameter “Resource/GetNodes”.

What is the response of this request?
Are there any related errors in the MODX error log (that get added when you try to reload the resource tree)?

yeah, there was an issue with Collections, so I got a 500 via the API …