Joplin opening screen won't display

I'm a new user on my second day with Joplin.

I imported several 'enex' files from Evernote extracts.
They seemed to work fine.

But, when I clicked on one of them today, I got this message.

Cannot call method 'getApplicationMenu' on missing remote object 8
Version info
Joplin for Desktop

Copyright © 2016-2020 Laurent Cozic
Joplin 1.3.18 (prod, win32)

Client ID: 8fe31ed3bc0248559e683bc7cfc0345b
Sync Version: 2
Profile Version: 34
Keychain Supported: Yes

Revision: 6b75485a1 (master)

I can't seem to recover from it. How can I get Joplin to open again.