"I cannot open my database file on my PPC. It can be opened with my PC software without any trouble. I can see entries count in statistics but no entries in main screen. When I try to add any entry or vehicle, I get an error message about SQLiteException."

Please open the installation path on both (on the desktop and your device) with file explorer and delete the file “config.mvc”. Then start Mobile Vehicle Admin and you should be able to configure the application.

Please take care of the decimal separator set in the options menu to be correct for your local culture info.  To avoid possible data loss please make a backup of your database which is stored usually in “MyDocuments”.