I have a functioning helpdesk with a database full of tickets, but when I go to the web interface, Deskpro is prompting me to go through the installation process. What's happening?
Check in /data within your Deskpro installation directory for a file called is_installed.dat.
The presence of that file is what tells Deskpro that installation was completed. The problem may be that is_installed.dat was accidentally deleted, lost during a server move, etc.
If that file is not there, create it (the contents doesn't matter).