Manager crashes with macOS 11 (Big Sur)

[Tut]

See this response from the developer in another thread:

Business database not valid, desktop version on Windows 10

Here is the solution. Install version 20.9.89 which will still allow you to import this old database format and will convert to SQLite format. Release Manager 20.9.89 · Manager-io/Manager.msi · GitHub Once you’ve done that, you can upgrade to the latest version.

Ignore the fact that the other thread was about the same problem in Windows. The point is that you need a version old enough to still include the conversion script.