When it comes to DNN, it is best searching for proper answers on the matter in DNN's forums as the configuration of the RadEditor is done by the DNN's developers.
What can help us determine the situation and investigate it is to provide a simple ASP.NET page that demonstrates the issue with the RadEditor control.
On a side note, as suggested in this forum thread
, you can check if any of the solutions provided in this KB article
can help resolve the issue.
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