Calibre 5.41 : Editor doesn't start
 

Windows 64 bits - 10.0.19041
I just updated calibre from 4.23 to 5.4.1.

Usually I run Edit e-book via a right-click in Windows file explorer > Open with.
But in 5.4.1 the editor doesn't start.
I tried to run it from the start menu. No result.
I launch calibre, right click a book in my library > Edit book. No result.

No message, no error, nothing. The task manager doesn't show anything.
The editor seems to be dead.

Any idea what's going on ?

Thanks.

Most likely an antivirus software issue. Some AV software can take a dislike to Calibre in a big way.

Just temporarily shutdown your AV software and then try to run the Calibre editor. If it works then there is an issue with the AV software.

If it really is your AV software, then delete it as no AV worth anything should be blocking Calibre.

I'm using the native AV, Windows Defender. I've tried to deactivate a few things (I'm not really sure what I should deactivate), add an exclusion but nothing changes. I even restarted the computer.

Thanks for the suggestions.

One a command prompt and run

calibre-debug -t

and post the output

That put me on the right track : "SyntaxError: invalid syntax" in a plugin.
I removed this plugin and the editor works again.

Thanks Kovid !

(Note : this a private plugin, not a plugin from mobileread)