I have a Sony Xperia M2 (not rooted) on 4.4 kitkat, and recently it started giving errors whenever it tries to move files to my external SD card. My internal storage is almost full, and it sometimes gives me notifications to move files to my external SD to clear up space. However when I tap it to actually move files, it fails with
Transfer interrupted. Check SD card for partially copied files.
In fact, no apps seem to be able to write to the SD card at all. In terminal emulator, I get this
$ cd /storage/sdcard1 $ mkdir test Failed to create 'test': permission denied
What happened, and how can I fix this?