What was the original reason for placing that "purely fictional" disclaimer before or after a movie?

You'll see that on the copyright page of most fiction. It's to protect the writer of filmmakers from lawsuits in case somebody should decide that characters ar events might be based on them.

omg rotflol ok ive have been given a pair thier is a blonde burnet and redhead and that all of them have been given the electrical powered chair for against the regulation they didnt dedicate so the pink head is going first and he or she sits down and the guy whoes approximately to throw the change yells waiting purpose and he or she yells tornado anybody seems around and he or she escapes the burnet caught directly to this and sits interior the chair waiting purpose huracane she yells and gets away the blonde is conscious sits interior the chair waiting purpose she yelled hearth ok so a similar scene because of the fact the 1st one they're getting the chair and the burnett sits in it first they ask her is she has any final words she suggested i take place to be a lawer and that i be attentive to justice wont kill me off so he throws the change no longer something happens the pink head sits down and he asked her if she had any final words she exchange right into a sparkling age form guy or woman and he or she suggested karma wont enable me die so he flipped the change and not something handed off the blonde sits down and suggested i take place to be a technicion and that i be attentive to that in case you dont plug it in its unlikely to kill all of us

To keep The Lawyers at Bay

People may go away thinking the movie was based on facts.

Prevents lawsuits based on defamation.

I see that same disclaimer in novels, as well. Probably just to avoid lawsuits.