Jon Jones -- FAILS DRUG TEST ... Out of UFC 200

Jon Jones hit the self-destruct button ... again.

The UFC superstar has failed a drug test and has been removed from his fight against Daniel Cormier at UFC 200. Yes ... seriously.

The Nevada State Athletic Commission notified the UFC that Jones tested positive for a banned substance -- though UFC has not revealed what the substance was. The test went down in June.

Brief history lesson -- Jones failed a drug test last year ... and that time it was for cocaine. Following the test, Jones said he wasn't an addict but rather made a bad decision.

Dana White says the situation is “obviously super, super disappointing."

Daniel Cormier has already weighed in saying -- "More than anything, just really disappointed."

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