Cannot access Admin area after upgrade

[Sartavos]

I upgraded from 1.1.4 to 2.0.3b and I now get this error message when clicking on the admin panel.

Fatal error: Cannot redeclare optimizetables() (previously declared in /home/www/web1140/html/forum/Sources/ManageMaintenance.php:1300) in /home/www/web1140/html/forum/Sources/Admin.php on line 306

What's the problem? 

[jossanaijr]

Re-upload the entire Sources directory from an SMF 2.0 package (doesn't matter which one) and make sure the files are being overwritten. The optimizetables() function was moved to ManageMaintenance.php in 2.0.

http://www.simplemachines.org/community/index.php?topic=229052.0

[Sartavos]

Thank you!