MailClient.Storage.Data.DatabaseCorruptedException (0x80004005): SQLite Error 11: ‘database disk image is malformed’.
If running the database repair makes no difference as @skybat advised above and all your other apps are ok and scanning your hard disk has no sector errors as @TimTom420 advised then suggest next to create a new database to test.
To create a new database first “close eM Client” and then go to the following hidden database folder below and “rename it” to eg: eM Client-Old Then reopen eM client and setup as new.
(Hidden database folder Windows)
C:\Users%username%\AppData\Roaming\eM Client
If creating a new database then fixes the errors and runs ok “but you need mail, contacts etc out of your original database”, then see my post in the following thread which explains how to do a Partial Restore either from a recent eM Client backup.zip or from a backed up hidden database folder if you backup your computer user profile.
Or see the following eM Client blog page on doing a “Partial Restore” in “Offline mode” part way down the following page.