No contacts in People, Phone and Messages apps

@martind - If Whatsapp can see your contacts, then presumably, there is a problem with the jolla contacts application.

In terminal, type in; pkcon remove jolla-contacts and then pkcon install jolla-contacts.

I've just tested on my other jolla, you can safely remove the contacts app and reinstall it without losing/deleting your contacts.

There are two separate contacts databases: privileged (which stores data shown by jolla-contacts etc) and non-privileged (which stores local-only data, which is shown by Android apps etc).

They are located at /home/nemo/.local/share/system/privileged/Contacts/qtcontacts-sqlite/contacts.db and /home/nemo/.local/share/system/Contacts/qtcontacts-sqlite/contacts.db respectively.

Please check your privileged database to determine if it is corrupted. Doing devel-su sqlite3 /home/nemo/.local/share/system/privileged/Contacts/qtcontacts-sqlite/contacts.db "pragma integrity_check;" should tell you that.

I have just observed something like that, after the update to 2.0.5.6 everything was working and my calendar and contacts was intact.

After a reboot, everything from my calendar and most of my contacts (all with the exception of 3 added recently on the phone), had disappeared.

A sync with my owncloud solved the problem, but does not explain the behaviour.

Thank your very much for commenting on my post. I think @chris.adams, you are right. I tested both databases with your bash command and the privileged one is "Error: disk I/0 error" while the non-privileged ones just says "ok". How can I solve the problem now? Should I delete the corrupted one and copy the non-privileged?

Unfortunately, the non-privileged database has a different structure and cannot be used to replace the other. My first advice would be to free up some (i.e., a few hundred MB at least) space on your device and then try to copy the database somewhere (e.g., /home/nemo/backup). I suspect this is a BTRFS issue...