The June 2017 fix had some side affects, have they been fixed?
The June 2017 fix had a side affect that it restricted file uploads from Rad Editor to a handful few only. Adding of new file extension often resulted in "Cannot deserialize dialog parameters. Please refresh the editor page" error.
Now you may upload other file extensions also by going through the steps below. The example is trying to add mp4 as a new extension in the system.
1. Include the new extension under Allowable File Extensions under Host > Host Settings > Other Settings in pre 9.0 or Persona Bar > Settings > Security > More > More Security Settings in 9.0 or above
2. Include the new extension under Document Manager Settings under Host > Html Editor Manager > DotNetNuke.RadEditorProvider > Everyone node in pre 9.0 or Persona Bar > Settings > Site Settings > Site Behavior > More > Html Editor Manager
3. Add an entry "Dnn.Telerik.Upload.AdditionalWhiteListExt" in web.config. More extensions can be added with comma in between them, e.g. mp4,.mov
One needs to be careful with mime settings while supplying arbitrary file extensions such as .xyz or .abc. You may still upload those, but you may not be able to download them via browser. Known good file extensions should not have any problems in downloading via browser.
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