Error: Failed to write file to disk

Hi,

Xibo has been working for a long time without any errors. Suddenly last week the system started reporting the issue “Failed to write file to disk”, for image uploads performed (small files having the same size as being update weekly in the past). Alltough the file system doesn’t seem to be full we already have performed a cleanup of old non-used files. Unfortunately no success up to now.

Does anybody have any ideas for the next step?