Additional SD card remounts itself as read-only In my Galaxy SII there was everything ok for three years. All this time I used an external 64Gb SanDisk card.

Now after some uptime the card is remounted as RO. All the modifying operations on the card seem to be succeed but after reboot I see all the directories and files still there in an old state.

I didn't notice when this is happening exactly, but suspect that this behaviour appears after I run newly updated version of OsmAnd+.

Any thoughts?
Most likely there is some filesystem corruption on the SD card. Try scanning it with a filesystem checker on your PC (e.g. fsck under Linux).