"global" Inbox DTTG: no sync after upgrade to DT 3. from DT 2

I installed DT 3 (without removing the 2.0 office pro version…).
Than I opened in DT 3 my 3 old databases from DT office pro 2. No problem.

BUT: when there is a sync (via dropbox - 1 database) between DT 3 and DTTG,
only the inbox of DTTG will not be synced with the inbox of DT 3.
Files in the database no problem.
On the iPhone I had to move the file from the inbox to my DTTG database-inbox,
then it comes from iPhone to the DT 3 database-inbox.

I think, the DTTG global-Inbox is still connected with the old DT 2 Inbox?
Both inboxes are shown in the finder (….application support…).
In DT 3 its named inbox.dtBase2 22.12.2014/24.10.2019 with the new icon.
In DT office pro 2 also inbox.dtBase2 22.12.2014/22.10.2019 also with the new icon.
(I have to admit, there are digital pieces since DT 1.0)

I have too less knowledge to remove, erease, shake and such things
without knowing, what I do…… Thanks for Help.

Best wishes from Munich

You should not run DEVONthink 2 and 3 on the same account, on the same machine. At a minimum, you should delete the DEVONthink 2 application from the /Applications folder.

Hi Bluefrog,
thanks for your answer.
I didnt run DT2 and DT3 at the same time. I didnt remove DT2 before installing DT3.
Deleting DT2 only in the app folder is not enough. I found afterwards in the application support folder inboxes from DT2 with the icon of DT3 but the time of built was long ago.
Perhaps during the installation of DT3 the prog found this old files and hijacked them?

I got the message:
Devondrop.dtcloud can not create database folder, path is still existing.

best wishes