This applies to both ASP.net 1.1 & 2.0.
If you have any errors with your asp.net website, do the following:
Login to Helm Control Panel
Click on domains
Click on the domain name having issues with ASP.Net
Click on website options
Check that the correct ASP.Net version is installed. e.g 1.1 or 2.0.
Then click save.
If this issue does not fix your error, contact our support department.