Just updated to Android 6.0 Marshmallow. Locus is the only app which has problems:
- can't find previous tracks or points and won't let me restore from backup
- can't find themes (even though they are all still there in the same place as before)
- can't find offline vector maps (even though in the same places as before) and won't let me select the dir where they are located
- briefly shows an error message "Unknown error (code 14) Could not open database",
I have not changed anything. Locus was working perfectly. I updated Android and Locus failed as described.