Hello, my devon think 2 suddenly stopped opening. I
Welcome to our forum. If you give us a bit more context we might be able to assist you better 
Sorry, I pressed “create” too early….
My point is: I use Devonthink Pro 2 since 2017 without any problems. Yesterday though, it did not open, giving me the message:
When I click “reopen” the problem remains, giving me the message (in Dutch) saying to Reopen, Ignore or Report (to sent a report to Apple).. Clicking on Reopen, the same message reappears.
Which version of macOS do you use? DEVONthink 2.x is not compatible to macOS 27.x Golden Gate.
The problem started with Tahoe, then trying to solve it I upgraded my Mac to … Golden Gate.
So I guess, I need to buy a the latest Devonthink version? But can I migrate my data in some way, not being able anymore to open Devonthink 2?
DEVONthink 4 is able to open the databases (.dtBase2). But first I would suggest to do a backup of your databases and to open a support ticket by sending an email to support - at - devon-technologies.com. Please attach the crash reports too. Thanks.