Each datastream in Fedora records has a internal ID which is unique to the datastream in the record. The Fedora ID has a maximum length of 64 characters, which can prevent Fez from creating supplementary metadata for file names over 50 characters (e.g. JHOVE output and thumbnails), as Fez uses a combination of filename plus unique suffixes for assigning IDs to derived datastreams.
See attached image, area 1.
Example of bug (area 1)
Logged In: YES
user_id=1331369
Originator: NO
Yes this is a problem. We'll need both a javascript validation and post upload validation check for this.