I managed to reproduce the null reference exception issue. It will be addressed in the upcoming service pack. In the meantime, you can set the property at run-time after the InitializeComponents method call. For the upcoming service pack our goal is to fix all critical and known issues regarding RadRichTextBox control. We know about the performance issues. They will be improved in one of the next major releases.
I did not manage to reproduce the spell checking issue. Could you illustrate the exact steps that we should follow to achieve it?
I updated your Telerik points.
the Telerik team
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