Festivals do not usually die at 9:25 in the morning. Marco Carola's Music On did, on 9 May 2026, with 20,000 tickets sold and the gates due to open at noon. The reason was not the lineup, the weather or the money. It was a tent, and a paper trail that nobody closed in time.

What actually went wrong?

The permit existed. Music On received it on 16 March. One day later, on 17 March, the promoter told the municipality it wanted a different structure: a round tent without the sight-blocking support pillars of the original. Practically, a better room for a 20,000-capacity rave. Bureaucratically, a new thing that needed signing off.

That sign-off never came in a usable form. Amsterdam's environmental agency had to give a safety assessment on the new tent, and on 5 May, four days out, it told the city it could not return a positive one. With no clean safety verdict on the structure people would actually stand in, the mayor revoked the permit on the morning of the show.

Whose fault is the delay?

This is where it gets uncomfortable for everyone. According to NL Times' post-mortem, the city sent reminder emails on 13, 23 and 30 April and again on 4 May, chasing answers after the promoter said it still had not heard back. Read one way, that is a promoter waiting on a slow agency. Read another, it is weeks of warning signs before a negative verdict landed with four days to spare.

Music On's own statement frames it as a system collapse: the city requested extra documents on 25 March, raised no substantive objection until 6 May, then went from "everything is in order" the day before to a dead permit hours before opening. The promoter called it "a system that failed everyone."

Confirmation the day before that everything is in order, then revocation hours before doors. That is the gap promoters now have to insure against.

Did the court change anything?

No. Music On filed an emergency injunction and lost. The court ruled the mayor holds discretionary authority over public safety and was entitled to rely on the environmental agency's negative advice as grounds to doubt the tent. Crucially, the court did not itself decide whether the tent was safe. It only decided the mayor was allowed to act on the advice he had.

For ticket buyers, the landing is soft: tickets stay valid for the next Amsterdam edition, or you can claim a refund.