Hi,

For users having issue with Sage CRM 6.2 and up. You can follow this instruction :

http://community.sagecrm.com/partner_community/b/hints_tips_and_tricks/archive/2010/08/19/the-error-is-in-the-details-making-sense-of-http-500-errors.aspx

But, I found another issue this issue is related to the UAC control. DISABLE IT and your CRM will work.

to disable UAC :

Start, run, msconfig, Tools Tab, change UAC setting, Launch, Lower the level to the floor, Apply and Reboot the Server.

Thanks,