Nick Swardson Escorted Offstage at Comedy Show After Bickering with Crowd

2:59 PM PT -- Nick Swardson just addressed Sunday night's debacle, writing ... "Just casually woke up on TMZ. Travel tip: don’t drink and take edibles in high altitude. F****** brain diarrhea. I’ll make it up to you Beaver Creek!"

11:02 AM PT -- TMZ has gotten ahold of the email sent to ticketholders for Nick's show Sunday, and the apology from Vilar Performing Arts Center continued in writing.

The message from them read, "We apologize for the negative experience you may have had at this evening's performance with Nick Swardson. Unfortunately, this show did not meet the Vilar Performing Arts Center's standards as a world-class presenter of the performing arts."

They continued, "Therefore, all tickets will be refunded to the original payment method. Please accept our sincere apologies, and be in touch if there is anything we can do to further assist you." Eyewitnesses tell us Nick got yanked from the stage just 20 minutes into his set.

Nick Swardson got the hook at his own standup comedy show this weekend after he started getting into it with the crowd ... who were not amused, and who made it known too.

The comedian -- known for his work on "Reno 911!" and his frequent appearances in Adam Sandler flicks -- was filmed Sunday shouting at and arguing with the audience in Beaver Creek, CO ... where he was hired as the headliner at the Vilar Performing Arts Center.

Nick appeared determined to continue on with the show -- despite things obviously going not-so-great ... as he shouted at the crowd, "Let's go," over and over again. It was a scene.

During his set, brief as it was, he also mentioned late comedian Norm Macdonald ... who he had said he was missing in a poignant Instagram tribute back in February. Sounds like those feelings poured out here onstage as well, 'cause Nick was reminiscing on his friend.

While some attendees expressed their discomfort over Swardson's unruly display ... others cheered on the comedian -- but Swardson was eventually guided off the stage after his mic was cut and the spotlight turned off, giving a little wave and a shaka sign as he sauntered away.

Shortly after Swardson's exit ... the director of operations made his way onstage and informed the agitated crowd that the show had officially ended early. He apologized, and promised refunds would be issued.

Unclear what exactly was going on with Nick ... but some have suggested he might've been under the influence -- although, it's hard to say for certain. He was definitely off, though.

We've reached out to his reps and the venue for clarification ... so far, no word back.