I just updated Nextcloud to the latest version, but it has uninstalled because of unmet dependencies.
I am running a Linux Mint system (Xenial). See error below:
The following packages have unmet dependencies: nextcloud-client : Depends: libqt5webenginecore5 but it is not going to be installed Depends: libqt5webenginewidgets5 but it is not going to be installed E: Unable to correct problems, you have held broken packages.
Is there a way to revert to the previous version?
Search if there is still the previous package on the repository,
apt-cache policy nextcloud-client
so you know if you can downgrade.
If you see the previous release then you could use,
apt install nextcloud-client=previous.number.version
Cheers!
Unfortunately, this leads to an error:
“Unable to correct problems, you have held broken packages.”
Martien
What about
apt-cache show nextcloud-client ?
It mentions this:
Package: nextcloud-client
Priority: optional
Section: devel
Installed-Size: 3902
Maintainer: István Váradi ivaradi@varadiistvan.hu
Architecture: amd64
Version: 2.5.0-20181111.015125~xenial1
Recommends: libgnome-keyring0
Depends: libnextcloudsync0 (= 2.5.0-20181111.015125~xenial1), libc6 (>= 2.14), libgcc1 (>= 1:3.0), libqt5core5a (>= 5.5.0), libqt5dbus5 (>= 5.0.2), libqt5gui5 (>= 5.3.0) | libqt5gui5-gles (>= 5.3.0), libqt5keychain0 (>= 0.3.0), libqt5network5 (>= 5.5.0), libqt5webenginecore5, libqt5webenginewidgets5, libqt5webkit5 (>= 5.0.2), libqt5widgets5 (>= 5.2.0), libqt5xml5 (>= 5.0.2), libstdc++6 (>= 5.2), nextcloud-client-l10n
Filename: pool/main/n/nextcloud-client/nextcloud-client_2.5.0-20181111.015125~xenial1_amd64.deb
Size: 1794716
MD5sum: 76371d7a17378de5cdae4263feae9c07
SHA1: 0f3779ad82370cd2ec7c7b7a0d29e78647850247
SHA256: 992b30b0f52af5a7f0980a4ab04543af7346c20901bbaa232b1a10dd377b8808
Description-en: Nextcloud desktop sync client
Use the desktop client to keep your files synchronized
between your Nextcloud server and your desktop. Select
one or more directories on your local machine and always
have access to your latest files wherever you are.
Description-md5: 80dc705b629ab106c8c5bf72a7bf84a1
Package: nextcloud-client
Status: deinstall ok config-files
Priority: optional
Section: contrib/devel
Installed-Size: 2871
Maintainer: István Váradi ivaradi@varadiistvan.hu
Architecture: amd64
Version: 2.3.3-20180415.190957~xenial1
Config-Version: 2.3.3-20180415.190957~xenial1
Depends: libnextcloudsync0 (= 2.3.3-20180415.190957~xenial1), libc6 (>= 2.14), libgcc1 (>= 1:3.0), libqt5core5a (>= 5.5.0), libqt5dbus5 (>= 5.0.2), libqt5gui5 (>= 5.0.2) | libqt5gui5-gles (>= 5.0.2), libqt5keychain0 (>= 0.3.0), libqt5network5 (>= 5.4.0), libqt5webkit5 (>= 5.0.2), libqt5widgets5 (>= 5.2.0), libqt5xml5 (>= 5.0.2), libstdc++6 (>= 5.2), nextcloud-client-l10n
Recommends: libgnome-keyring0
Conffiles:
/etc/sysctl.d/101-sync-inotify.conf a4b015d9a5dc4ea142b9cee49b4830c9
Description-en: Nextcloud desktop sync client
Use the desktop client to keep your files synchronized
between your Nextcloud server and your desktop. Select
one or more directories on your local machine and always
Try,
apt install nextcloud-client=2.3.3-20180415.190957~xenial1
I think I solved this by installing Nextcloud-2.5.0-x86_64.AppImage
That would be my second option.
I can’t manage to launch it on startup though, have to do it manually 
Still did apt install package=version let you roll back?
No, I could not roll back.
How do you start it manually? (I cannot find any icons in start menu or tray 
Mmm,
then you should fix your apt or you’ll find errors later.
apt install -fy
should fix it.
I’ve edited my menu to launch the App package, otherwise just double click the App file to launch.
Perhaps you could help, I just cannot find the App file only this output from whereis:
nextcloud: /usr/share/nextcloud
They are not stored the same way that deb packages, so you won’t find them there.
I haven’t taken the time for a closer look of the App package, but IIRC they are localy storaged on your home user folder.
Take a look at .local or .config there you may find something.
If you do please, share back 
Nothing in these folders.
But … I did a reboot, and it does work now.
Am sorry to hear you cannot get it to work at startup - I hope NC engineers can help you out
Ok, don’t worry, my machine reboots once a moth or a quarter. So no big issue there.
Glad it works fine for you.
See you around.
In case this helps others, I fixed this situation by upgrading Mint Sylvia (18.3, based on Ubuntu Xenial) to Tara (19, based Ubuntu Bionic).
I could then reinstall the nextcloud-desktop package from the PPA normally.