Hi,

i just ran into a weird problem and wanted to share this information with anyone who might need it. Dotnetnuke seems to ship a version of the System.Web.Extensions DLL (for ajax support i presume). Usually no problem. Unless another assembly needs another version of this assembly.

In my example a crystal reports (version 10.5, shipping with VS 2008) viewer failed to load, causing an exception as it was not able to load the assembly "System.Web.Extensions", Version "2.0.0.0". When opening the web site with VS 2008, the project settings stated that the assembly was referenced from GAC. After upgrading the target framework to 3.5, i still got this exception. I double and triple checked my web.config for missing or wrong assembly references, but everything already pointed to the new version 3.5. At last, i took a look into the bin directory and found the assembly. After deleting it, the crystal reports viewer control worked and was able to display my report. I checked the Dotnetnuke installation archive (Version 4.8.2) to verify that this assembly was indeed not copied over by vs but installed / shipped by dnn.