Hello @ShootNick! Welcome to Ext.NET forums!..
The example you pointed works to me. I thought you pointed the example as it was a sample of the failures?
If there's more to the example to reproduce the issue you are facing, please provide a test case so we can reproduce it... With MVC it can be tricky to come up with simple and runnable test cases but with a little effort we're sure you can do it!..
The code sample you provide should include only the minimum amount of code required to reproduce the issue. Code unrelated to the issue is to be removed. Anyone should be able to copy + paste your sample into a local Visual Studio test project and run without having to make modifications.
Tips for creating simplified code samples
If Exceptions or syntax errors are thrown when testing your code sample, we'll let you know so you can revise your original sample. Then we'll review again with the updated sample.
When posting your code samples in the forums, please paste that sample within
tags will add formatting and syntax highlighting to your sample.
The following two forum posts provide many excellent tips for posting in the forums:
1. More Information Required
2. Forum Guidelines