withmore,
If your application is running asp.net 1.1 framework, please use the CuteEditor.dll under Demo\Framework 1.x\bin.
If you are using CuteEditor.dll for 2.0 and 3.5 under asp.net 1.1 framework, you will receive the above error.
asp.net Chat http://cutesoft.net/ASP.NET+Chat/default.aspx
Web Messenger: http://cutesoft.net/Web-Messenger/default.aspx
asp.net wysiwyg editor: http://cutesoft.net/ASP.NET+WYSIWYG+Editor/default.aspx
asp wysiwyg html editor: http://cutesoft.net/ASP
asp.net Image Gallery: http://cutesoft.net/ASP.NET+Image+Gallery/default.aspx
Live Support: http://cutesoft.net/live-support/default.aspx