Ginger, (I am assuming this Anonymous Monk is Ginger again) you can display an informative message when an open fails as follows:

    open FILE, "bigfile" or die "Open failed because: $!\n";
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What if the reason open failed is not "file too big to be opened?" What if it is "this account does have read permission for bigfile?"

Revealing the mystery operating system and including a copy of the ls -l or dir, or whatever that might provide sufficient clues to us hapless volunteers to get you where you want to go. Something I have ruled out has been the source of my problems; perhaps the same is true of yours. Bob