Revolve Festival was a nightmare for a ton of influencers ... and social media star Olivia "Livvy" Dunne was no exception -- the LSU gymnast says someone made off with her phone!!
Of course, the complaints piled in about the super-exclusive bash during Weekend 1 of Coachella ... with folks claiming they were stranded in the heat at shuttle stops without water or any other way to make it to the venue.
Dunne says her experience wasn't all gravy, either ... sharing a pic in a pink outfit while breaking the bad news.