After a migration from Tridion 5.1 to SDL Tridion 2011 I am having a problem when I try to edit the features in Rich Text Formatting fields in some schemas. In the schemas with the issue I cannot edit the fields because the window is opening empty with only the confirmation button.
In the other schemas with Rich Text Formatting fields I have no problems editing the Xslt filtering option.
I have also tried refreshing the window by pressing F5 not just once but many times and the result was almost the same as it opens the window but the window is still empty. If I edit something in there it's not possible to save the changes but as I said, it happens only in some schemas, not in all.
Could anybody help me? It's SDL Tridion 2011 SP1-HR1.