"In Use" problem

I am unable to reach any database on a new mac due to another instance being “in use”. I recently had my computer upgraded and removed the license from the prior machine. Nonetheless, I still can’t access DT with my license on this new machine. How can I remedy this?

Are you trying to access databases in a shared location?
Are you trying to run DEVONthink Pro and Pro Office simultaneously?
Does this occur with one or all databases?