Server or Connection problem: Database access returned an invalid response
This appears to be isolated to Windows users and also shows up as error: "Invalid response from database. Password could not be set"
If you are using OfficePool 2013 1.0.2, you will need to either downgrade to 1.0.1 or download a newer release, if available.
Here is a link to version 1.0.1: http://officepool.pachysoft.com/downloads/officepool2013_setup_v1.0.1.exe