I do not think there is a specific page as to what the error is and the resolution for that error or atleast the explanation for the error.
But, you can use this link to figure out some of the possible solution for a particular error message from the VPN client.
http://www.cisco.com/en/US/customer/support/tsd_tac_case_collection.html
Click on "TAC Case Collection"
Choose security and for eg., insert this error message "error message secure vpn terminated locally by client reason 412"
You will get possible solutions for the problem.
Hope this guides you in the right direction.
Rate this post, if it helps.
Cheers
gilbert
