Hi there - I have an old manager version on my old macbook, but I can’t update it because apple doesn’t support any more OS updates. I got a new macbook I am trying to import the manger file to, but it says can’t open because the database is invalid.
This business database is not valid. Manager data is stored in SQLite database. However it appears the file you are attempting to open is not a SQLite database.
Search the forum you would have found entries such as by @Tut here History has no Search Option - #31 by Ealfardan which contains the explanation why the database changed to SQLite and how to update and old system to this new database.
UPDATE: By the way, this has nothing to do with the Apple operating system. If Manager runs on your old Macbook then any new version of Manager will do also.