Troubleshooting: Database in Use
If your system crashed while DEVONthink was running, it may leave a file behind in the DEVONthink folder named "DEVONthink.lock". The next time you open the application, DEVONthink might refuse to launch until you delete this file or tell DEVONthink to ignore it. This is done to prevent two different versions of DEVONthink from accessing the same database. To continue, make sure that no second incarnation of DEVONthink is running and choose "Ignore".