Cops to Rihanna -- German Man is No Stalker ... Just a Deutsche Bag

The German dude who trespassed on to the property where Rihanna is staying in Barbados is not a stalker and poses no threat ... he's just a moron ... this according to police.

We broke the story, cops were called to the property when the random German guy swam up to Rihanna's beachfront villa yesterday ... and tried to walk in like he belonged. He clearly did not.

Cops tell us ... officers spoke with the man and determined it was all just a giant misunderstanding. We're told the guy simply didn't realize he was entering private property, despite the fact there was a large security team standing guard.

He was not arrested -- and police say he's not in trouble at all.