"There was a problem playing this item"

Hi everyone

I suddenly get a lot of "there was a problem playing this item" messages. I read it has something to do with diskspace but I'm not sure this is the problem...

fish@plex:/$ df -h
Filesystem                    Size  Used Avail Use% Mounted on
udev                          7.8G     0  7.8G   0% /dev
tmpfs                         1.6G  9.5M  1.6G   1% /run
/dev/sda2                     102G   49G   48G  51% /
tmpfs                         7.8G  180K  7.8G   1% /dev/shm
tmpfs                         5.0M  4.0K  5.0M   1% /run/lock
tmpfs                         7.8G     0  7.8G   0% /sys/fs/cgroup
/dev/sda1                     511M  3.6M  508M   1% /boot/efi
cgmfs                         100K     0  100K   0% /run/cgmanager/fs
//192.168.0.7/video/TV Shows   21T   14T  7.9T  63% /media/tvshows
//192.168.0.7/audio            21T   14T  7.9T  63% /media/music
//192.168.0.7/video/Movies     21T   14T  7.9T  63% /media/movies
//192.168.0.7/photos           21T   14T  7.9T  63% /media/photos
tmpfs                         1.6G   72K  1.6G   1% /run/user/1000

My plex temp dir is set to default. I never changed it.

Do you need logs? Which ones?

Thanks for help!