Thank you for the report.
Yep, I am aware of that.
From Catalina, macOS has changed how Gatekeeper works.
Each app now has to get notarized in addition to signing it:
Thanks, I am able to install and use that one.
I gave it a quick runthrough and confirmed I can:
Launch and use normally
Export to md
Import from md
load plugins (standard + mermaid)
ipm-beta install works normally
I donāt have a printer, so I was unable to test that, but the print dialogue did appear.
I did have a crash when attempting to delete a notebook. I submitted the report to apple, but I was also able to delete the notebook successfully after restarting the app.