I think the problem is the name of the parameter (block). If I remember correctly it has to be called either currentContent or currentBlock. That is because the model binding is looking for a parameter called that to bind the model to.
You are completely correct, Per! Thank you very much for the response.
Ha ha, had the same issue with pages, this is the list of working parameter names:
This is our defined block type:
And this is our block controller:
The problem is that the block parameter to the Index method is null.
Everything works fine when I have a view named "RowBlock" (i.e. without a controller), but when we introduce a controller the block is null. Any suggestions to why this might be?