Hello mtginfragistics,

You can try the following steps in order to resolve this issue:

Make sure that the file (same version and same build as inserted in web.config) is available in your GAC or in your Bin folder.

Make sure that you have cleared all temporary files that points to the different versions of the controls.

Clear the content of the licenses.licx and rebuild the project again.

Restart Visual Studio (sometimes the assemblies are kept in memory).

Let me know if you need further assistance with this question.

I am getting the same thing. I have to exclude the licenses.licx file and comment out that section of the web.config to get any programming done. Many hours lost tyring to hunt down the cause with no luck. I have uninstalled and reinstalled infragistics more times than I care to recount. To say I am interested in the solution would be an understatement.