I've upgraded an Asp.Net project from 3.5 to 4.5, and (using VS 2013) I'm having trouble getting the HtmlEditorExtender to work.
I've installed the new version of the Toolkit, set the tagPrefix to 'ajaxToolkit', and it works for the other Ajax extensions, but not the HtmlEditorExtender.
The extender is in the ToolBox, and I can drag it into the source and alter its properties, but it doesn't compile: Unknown server tag 'ajaxToolkit:HtmlEditorExtender'.
For the sake of comparison I created a new web project and after some difficulty due to the default setup for Ajax referencing the old ScriptManager, etc. I was able to get the HtmlEditorExtender to work in that environment. I don't see what code differences
there are between the new project and the upgraded project. I do notice that the "Solution" structure looks different: The old project lists AjaxControlToolkit.dll in the "bin" directory, where the new project show it under "references", I wouldn't expect
that to be significant.
Any ideas about how to analyze this problem?