Tim and Kevin thank you for your help.

I did everything you recommended and finally removed MM controls from the toolbox then added a new MM .NET Web Controls tab back to the Toolbox and added MM .NET Web controls into the new tab from Mere Mortals Framework Web Forms 2005.dll.

Now when I try to place any MM web control on the web form, I am getting following Visual Studio error message "Control cannot be created because Visual Studio cannot find the control's type in the control assembly."

Also, none of the web controls can be loaded on any form in my project. The same as it used to be before I made changes.