The instructions for this should actually show up as a suggestion when you get an Access Denied error when trying to load a custom assembly in ASP.NET (and by extension, SharePoint.) But for quick reference, here it is:
- Open regedit.exe.
- Navigate to HKLM\SOFTWARE\Microsoft\Fusion.
- Add a new DWORD entry named “EnableLog”.
- Set the value of the entry to 1.
- Reset IIS (at a command prompt: “iisreset.exe /restart”.)
Recreate the error. The ASP.NET error text should now include assembly binding information.