Here’s a little note on how to upgrade EPiServer CMS 7.x to EPiServer CMS 7.5.
Bug in property settings for TinyMCE
WidgetFactory: Could not resolve one or more widgets
My first thought was that I was missing the latest version of the assemblies for the EPiServer UI, but after some investigation, deployment and configuration review I found out that everything seemed to be ok with the binaries and configuration for the web site. Another thing that indicated that everything was correct was that I did not find any direct information among the reported bugs that existed for EPiServer CMS. In other words, it was either an unreported bug or something with my settings.
Since I didn’t find a solution to my problem I let it be a little while, but being a developer means that it is hard to resist to fix broken things, so after a little bit of brainwork I found out that the problem ought to be in TinyMCE and its settings.
The problem where the custom property settings that I used for XHTML properties. By some reason the previous settings made TinyMCE stop working.
I solved the problem by creating a new property setting for the XHTML property in Admin Mode, and set it to be default for all XHTML properties. That solved my problem.