File existence status is not updated in the cache after an operation which changes it for a given filename (e.g. move, delete), which causes weird errors (files do not disappear but become broken on delete; the file is displayed on the redirect page but not displayed on the new page after move). Purging the file fixes it.
original description:
During move, the file is not properly moved to new filename, only description page entries are.
Problem appeared today (2015-03-17) about 17:57 UTC, Concerns, for example, all entries from:
https://commons.wikimedia.org/wiki/Special:Log/Wieralee
moved between 2015-03-17 18:57 UTC and 2015-03-17 19:13 UTC
Moving the image back, deleting & restoring does not retrieve the file entry (only description page entries are available for restoring)