Can't install on Mac with High Sierra

Hi there.
I would like to install Mailspring on my MacBook with High Sierra.
I guess I did somthing stupid and moved the app from the download folder to the application folder while the app was lunching for the first time. It showed me some error message (can’t remember what exactly). I then deleted the app and the ~/Library/Application Support/Mailspring folder and restarted the MacBook.

When trying to reinstall Mailspring I get the error shown below. It says something like

"We discovered a problem with your local E-Mail-Database. Error: An unknown error occured (Mailsync: null)

Make sure that no other Mailspring instances are running and click “create new” to reset the local cache."

Bildschirmfoto 2023-07-28 um 12.31.22

Clicking the “reset” button does unfortunately nothing. The same error pop up window appears again.

Any idea what I can do? Any help would be much appreciated. Cheers.