I am having the exact same  problem posted by another DNN user on another forum at the link below

http://local.dotnetnuke.com/Community...

One suggestion was "Also make sure that the web.config and the asp.net application on the server are running the same version of .net. Having a .net 3.5 application on the webserver and a web.config set up for .net 2.0 will make the website throw errors at random and crash."

I noticed that the minimum requirement for DNN 5.2.0 and up  is .NET 3.5 SP1.  My web.config has references to .net 3.5. On my server, I have Microsoft .NET Framework 3.5 SP1 installed in the "Add or remove programs" list, however in IIS (version 6) under the ASP.NET tab my ASP.NET version is 2.0.50727 and the only other option in the dropdown list is 1.1.4322. Does this version in IIS need to be 3.5 which is a new requirement for DNN 5.2.0 and up?

Thank you in advance for all of your help!

Matt

Sebastian,

Thank you! I am running IIS 6. I was unclear about the .Net 3.5 requirements for my DNN 5 installation and the IIS 2 setting, but you cleared it up.

Thanks again.

Matt