by Ken Task.
In your screen shot, looks like Ghostscript it trying to make a PDF from the PDF file submitted Tigas 4.1 psomething.pdf - if that PDF file not compatible or is corrupt, then ghostscript can't render it.
Suggest downloading and opening.
Might also have to do a query of your mdl_files table looking for that pdf file name along with it's contenthash value.
Then use contenthash value to find the actual file in moodledata/filedir/
copy that file (contenthashed named) out to some location where can download it to see that way also.
'SoS', Ken
