Calibre not opening after update to 5.0

[Chich]

I installed Calibre 5.0 and am now getting this message whenever I try to open the software:



Tried reverting to version 4.23 but I'm getting the same error message. Any idea what might be causing the problem? (Using Calibre on Windows 10.)

[dunhill]

It also does not start in "Catalina" version. 10.15.6 Mac. No error sign appears

[kovidgoyal]

Uninstall, delete C:\\Program Files\\Calibre2
(or wherever you chose to install calibre). Then re-install. And
dont worry, uninstalling will not affect your books/settings

[Chich]

Originally Posted by kovidgoyal

Uninstall, delete C:\\Program Files\\Calibre2
(or wherever you chose to install calibre). Then re-install. And
dont worry, uninstalling will not affect your books/settings

I did just that and everything's working fine now, thanks!

[Snodgrass]

Slightly different problem here: calibre 5 doesn't recognise either of my Kobos.

Tested with three different Mac computers, four cables and two readers (Clara and Glo).

All computers running Mojave; shall try with Catalina on the morrow and report any progress.

Now downgraded (no problem) to 4.23 and all seems well.

Happy isolating, all.

Olly.

[Uncle Robin]

I got exactly the same error message as the OP when I selected "start Calibre" after the install, but oddly, Calibre has started fine every time since, and shows its version number as 5.0

[kovidgoyal]

@Snodgrass: That is a known bug on macOS fixed in the next release.

@Uncle Robin: That error is basically caused by an incomplete/partial installation. Usually rebooting, or re-installing take care of it. Looks like in your case simply restarting calibre did the trick.

[thiago.eec]

Originally Posted by Uncle Robin

I got exactly the same error message as the OP when I selected "start Calibre" after the install, but oddly, Calibre has started fine every time since, and shows its version number as 5.0

Same here.

[mbovenka]

Originally Posted by thiago.eec

Same here.

And here. 'Launch calibre' from install gave the error above, everything works fine afterwards.

[jiembe]

When I install calibre 5 I got this message (001).

I try the uninstall calibre as suggested and install again 5 and get the error message (002)

[kovidgoyal]

@jiembe: Try rebooting.

[jiembe]

Got again the message 001.

Window 10 Family 19041.508

Add: Did you ask me to reboot after uninstall or to reboot after installing 5 ?

Add 2 : This time I uninstall 4,
reboot,
install 5 and start it : error,
reboot: Working !

Thanks

[thiago.eec]

Originally Posted by kovidgoyal

@jiembe: Try rebooting.

I tested this: installed 5.0.1, then rebooted without opening calibre. After reboot, I got the same error when opening it for the first time. Subsequent attempts work just fine.

Looks like the error message always pop up on first time opening.

Windows 10 here.

[theducks]

Originally Posted by thiago.eec

Same here.

Same here.
I had also seen messages when I tried to run the beta (on 2 different W10 systems), but was unable to capture the message , so I blamed my system (has some other re-installs fail)
FWIW I just ran the installer (over the 4.x version)
The fail was when I used the desktop icon to launch.

I tried to capture a debug log (calibre-debug --g ) no joy

then I uninstalled, checked:calibre2 was already gone. Tried again and we had a GO

[mbovenka]

I had the same issue again upgrading from 5.0 to 5.01. 'Launch calibre' after install fails with the error message above, afterwards it works fine.

The 5.x MSIs have some weird issue.