Zorin OS is really good, but after two months of using it, some weird problems have emerged:
1. Mouse: After waking up my notebook from sleep, the mouse pointer isn't visible anymore. After a while clicking and moving around, the pointer is only visible at the taskbar. Maybe it has something to do with the nightmode? I sent the notebook to sleep on daylight and woke it after sunrise, where the nightmode got activated. 2. Nextcloud desktop client: I've set the app Nextcloud desktop client to automatically start at systemstart but it does not. Besides of that, the Nextcloud folder in /home/myname/Nextcloud has sometimes permission problems which leads to incorrect sync. I then have to rename the folders back and forth so that the client can sync them and don't show a: permission denied error 3. Drag&Drop: If I write a mail with Thunderbird and want to add an attachement by D&D from my Nextcloud folder, some file anywhere on the disc gets attached but not really, because its filesize is 0KB.
Seems a permission issue too, but even if I change a folder's permissions as sudo, nothing happens and the owner of the folder is displayed as 'user#755', not my name anymore.
I'd recommend breaking this down into separate threads to keep things organized.
Mouse pointer not visible after returning from sleep mode.
Nextcloud not mounting automatically, and intermittent permission issues.
Attaching files to Thunderbird via drag & drop.
Set the columns of one folder to a default for all.
Let's do one at the time, starting with #3 since it's likely the easiest to address.
As you saw from the thread you linked to, one possible cause for file permissions is due to the package format. Did you already followed the steps I mentioned over there to determine that? Launch a Terminal from the applications list and run:
flatpak list
If you see Thunderbird listed there, it's most likely a file permission issue. You can then install something called Flatseal from the software store, and use it to grant exceptions to wherever location that you need in your system:
I installed Flatseal and gave Thunderbird the permissions for 'All user files' but then it does not load my profile anymore, instead a fresh Thunderbird.
If I revoke that permission, everything is back fine again.
I gave Nextcloud the same 'All user files' permission in Flatseal and it seems the sync problem is fixed now. Thanks for that. It even looks like more functions from the app are now possible to use.
Normally, Thunderbird creates a hidden folder to store the profile information under your user's home directory (that's just the folder that you see when you launch the file manager, where you have your Documents, Music, etc.). Since the Flatpak version didn't have access to this location before, it probably used another location. Now that you used Flatseal to give it permissions to all files, it sees that there isn't a profile at the expected location, and creates one. That's at least my thinking...
You can fix that in one of two ways:
Since the goal is to enable drag & drop, at least for the time being, you could just pick and choose one or a few locations that you want to use for that purpose. The Downloads folder is typically already accessible, but you can also add Pictures, Documents, Desktop, etc. This should keep things relatively simple, with only a slight inconvenience in the sense that you need to remember about this.
If you prefer to add access to all files in your home directory, you can copy your current profile folder to the new expected location. Or, even better, just create a link that will effectively work in the same way but will allow you to backup your configuration much easier.
First you need to delete the new profile directory that was created after you granted access to all of your files.
Close Thunderbird, and open the file manager. On the settings, you can toggle visibility for hidden files, which will reveal a folder called ".thunderbird". Instead of deleting it, move it to your desktop or somewhere else; that will be enough and it's much safer, just in case.
Then, launch a terminal from the applications menu and run the following command:
This will create a link — a shortcut in Windows lingo — where Thunderbird expects to find a profile.
Last but not least, you can uninstall the Flatpak version and go with the native Debian package that will work as expected. Since you are already running things I would leave this for last, but know it's an option.