It was a fashion fiasco!Nicki Minaj threw a diva fit when she was told she couldn’t rehearse her song “Anaconda” multiple times before the Fashion Rocks 2014 concert last night, RadarOnline.com can exclusively reveal.“Jennifer Lopez ran through her song twice because the stage crew needed some extra practice for her scenery set up,” a concert insider tells Radar. “Then Nicki wanted extra rehearsal time, too, even though production didn’t need it.”When producers refused to bend to the wigged-out rapper, she nearly lost it.“She was acting completely out of control, and threatened to walk off the show,” the insider says. “The CBS executives told her she was being inappropriate, and that she should leave. They were planning to have Kiss perform two extra songs to cover Nicki’s time slot.”However, a truce was made, and the former American Idol judge performed a very risqué version of her new hit at the event, held in Brooklyn’s Barclay’s Center.But Minaj, clad in just a diamond bra and tiny jean skirt, upset network execs AGAIN by disregarding their warning not to dance so suggestively on stage for a CBS live broadcast.“Her moves were crazy,” the insider adds. “The camera crew had to cut away from her dancing at one point because she was basically having sex on stage.”Looks like the star won’t be invited back for Fashion Rocks 2015!