first I would hope you have a PostgreSQL Database Server up and running and the domain your trying to add to has postgre enabled ?
you should see something like this
the pull down on the right should show the available databases. I just installed it with no problems.
Did you just delete the directories /phpgadmin and /phpgadmin_2 rather than uninstalling from the from the manage web apps screen ?
Database is running and can be selected (I overlooked that, it worked in PhpMyAdmin without selection).
The new link created (1) generates the error (2). Apparently has something to do with OpenProject, as Apache reports that an index file is missing (OpenProject working path), which is correct but not necessary.
But the problem (3) remains that entries cannot be deleted - any idea about this?
"Did you just delete the directories /phpgadmin and /phpgadmin_2 rather than uninstalling from the from the manage web apps screen ?"