Unable to get property 'apply' of undefined or null reference

We just upgraded ext.net version from 3.2.0 to 4.8.3. After this upgrade we encountered a problem, both in Chrome and IE 11.

The view has a GridPanel that is filtered by three dropdowns. At some point the filter throws the following error on ext.axd script file:

'Unable to get property 'apply' of undefined or null reference'.


After some tests we found out that the error was thrown by the PrepareToolbar function used in one of the columns of the grid. We changed that, and now we are using PrepareCommand. The error is fixed in Chrome but persists in IE. Whenever we execute the code in debug mode, IE and Visual Studio both crash.


Thanks in advance!

Hello @Genta, and welcome to Ext.NET forums!

I'm going to be brief in the answer, as we can't really help with that you provided. We would need to be able to reproduce the issue you're facing in order to be able to help you, log an issue, or whatever it takes to be solved.

We have instructional threads to help you do so, if you are not really sure where to start:
- Tips for creating simplified code samples
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You can also randomly take a look at some forum threads in Premium or Bugs forums to see some samples of threads with code snips.

We're looking forward to your follow-up.