Matthew:

-Does it happen for all users?
-Does it happen consistently 100% of the time or only sometimes?
-Does it happen in other Adagio modules?
-Does it happen in Sample data?
-When did it start happening?
-What changed at that time or even recently?
-Does the error message let you continue or does it close Payables?
-What version of Payables?
-What version of operating system?

Or, if Support is right, try rebooting the server.