With MEGA 2009 SP5 CP6, the Advisor "Reset cache" button redirects to a missing page named "administrator_page.aspx".
To fix this issue, you can edit "C:\Inetpub\wwwroot\advisor\Admin\default.aspx.cs" and replace "administrator_page.aspx" with "default.aspx" at lines 100 and 122.
Another way to fix it would be creating a copy of "default.aspx" named "administrator_page.aspx".
Go to Solution.
This issue is followed by 30659. I will keep you informed once i get a feedback / solution for this solution.