Court records show prosecutors dismissed Kraft's 2 misdemeanor charges of soliciting a prostitute ... with officials saying Thursday they didn't have enough evidence to get a conviction.

"Although there was probable cause to make an arrest," state attorney David Aronberg wrote in court docs, "the evidence cannot prove all legally required elements of the crime alleged and is insufficient to support a criminal prosecution."

The news isn't exactly a surprise ... in fact, it was expected after Kraft's team of lawyers successfully argued video of the New England Patriots owner allegedly receiving sex acts inside the Orchids of Asia Day Spa should NOT be admitted in the case.

Judges in the Florida Fourth District Court of Appeal ruled cops screwed up in the way they went about recording inside the Jupiter, Fla. facility by failing to ensure privacy for people getting legitimate massages. So, the footage was not allowed in the case.

With the vid thrown out ... prosecutors clearly lacked a smoking gun -- and were essentially forced to move on.

State officials are expected to break down the decision at a press conference later Thursday.