Conor McGregor's Ireland Bar Catches Fire

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Conor McGregor's The Black Forge bar caught fire on Friday morning ... but the UFC superstar just revealed his pub sustained no significant damage in the blaze.

Law enforcement in Ireland says flames licked the Dublin establishment at around 3 AM ... though firefighters were able to put it all out before it ripped through the place.

No injuries were reported ... and an investigation into how it all started is underway.

McGregor -- who's currently still yachting off the coast of Europe -- said in a video from his boat his watering hole is "open for business" despite the issue ... without a scratch "on her."

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