15:40:29 <NamelessCoder> when TYPO3 copies records with flexform XML data and the flexform structure contains *ANY* file-type element, the value that is stored in the XML is a reference count (was before: CSV list of filenames). TYPO3 now tries to copy the file with the UID of the reference count (e.g. you have two relations, it tries to create new reference to file UID:2)
15:40:57 <NamelessCoder> result: if you're "lucky" the copied record has one resulting relation pointing to an unexpected file
15:41:43 <NamelessCoder> if you're "unlucky" the record contains no relations in the XML data field after copy (it still does contain the copied reference count but of course, any references were not copied and thus cannot be resolved to a value that can be displayed in a form or rendered in FE)
15:42:12 <NamelessCoder> this is very much beginning to look like a core bug fix is required...