Mindy Weiss, the most famous celebrity wedding planner in America, is being sued over a hoity-toity reception ... and the parents of the bride blame Mindy for botching a key Jewish tradition.

Barbara and Craig Spencer bankrolled a $2 million Aspen wedding in March 2022, for their daughter. They dropped $100k on Mindy, who's done weddings for Justin and Hailey Bieber, Ellen DeGeneres and Portia de Rossi, Patrick and Brittany Mahomes, Russell and Nina Westbrook, Paris Hilton and Carter Reum, as well as lots of Kardashian shindigs.

They say Mindy was overbooked and ill-prepared to pull off their lavish affair. They're also upset that the wedding was originally budgeted for $1 million, but Mindy ended up telling them shortly before the event that the cost had ballooned to double that. They hired a 12-piece band but the sound system sucked, and the father-daughter dance was barely audible. They tick off a number of problems that ticked them off ... notably, the ceremony started so late, the gondola that took guests to the venue only ran up to a certain hour and not everyone made it.

They hired Nelly to perform at the reception, but due to the delays, his performance had to be cut short.

But it seems the biggest thing that rankled them involved a tradition at most Jewish weddings -- a dance called the Hora. It's when the guests at the wedding hoist up the bride, groom and parents who are sitting in chairs and bob them around to traditional Jewish music.

According to the lawsuit, Mindy was warned the chairs in the reception room were much too heavy and that she should go with lighter chairs. Apparently, that didn't happen and as a result, the Hora dance was very brief and the father of the bride didn't get a ride!

Mindy's being sued for more than a million bucks. We reached out to Mindy ... she had no comment.

Mazel Tov to the bride and groom?