Unusual error message

Hello

I am getting an unusal error message when I start Calibre from teh task bar in W11:

[quote]

calibre, version 6.21.0
ERROR: Contacting calibre failed: Failed to contact running instance of calibre, try restarting calibre

Failed to connect to Listener at: \\.\pipe\CalibreGUI-DJLx with error: QLocalSocket::connectToServer: Invalid name

b'launched:["calibre.exe"]'

[end quote]

If I OK the dialog Calibre seems to work fine. But have un/resintalled twice and it hasnt gone away!

I will say that I fell into the trap of running the database on a shared drive between W10 and W11 and lost a chunk of my database, but I got over that and the database seems fine (not much data lost).

Could this be associated with some external software such as Java, .net, or whatever? Or other less obvious files that might need to be removed?

Not sure what to look at to fix.

Thanks for any advice.