With the international art calendar in disarray because of the coronavirus pandemic, the world’s biggest art fair has announced plans to call off its 2020 edition. Art Basel’s edition in Switzerland—one of three events held annually by the art-fair giant—has been canceled amid heightened uncertainty. It would have marked the fair’s 50th anniversary.

Earlier this year, Art Basel was moved from its normal dates in mid-June to a new set of dates in mid-September. Its online viewing rooms event will still take place as planned, running from June 19 to June 26, with preview days from June 17 to June 19. The next live edition of the fair is scheduled for June 2021.

In a release, Art Basel explained that it was forced to cancel the fair because of “the fundamental health and safety risks related to the pandemic, the financial risks for exhibitors and partners, the ongoing impediments to international travel, and the fact that the regulatory environment around large-scale events has yet to be finalized by the Swiss Federal Council.” The fair, which typically gathers just under 300 exhibitors, is considered one of the premier art events each year, and its cancelation comes as many of the summer’s most important biennials, from the Berlin Biennale to the Venice Architecture Biennale, have rescheduled this year’s editions for later dates.

“We are acutely aware that our galleries are facing unprecedented challenges and economic difficulties, and we had fervently hoped to support the art market’s recovery with a successful fair in September,” Marc Spiegler, Art Basel’s global director, said in a statement. “Unfortunately, the uncertainties that we face remain too high.”

The Swiss edition is the second Art Basel fair that has been called off in light of the coronavirus. The first was its Hong Kong fair, originally slated for March. Amid pro-democracy protests and an emerging pandemic, many exhibitors called on the fair to consider canceling the Hong Kong fair. In the end, the fair’s organizers agreed to cancel Art Basel Hong Kong this year and replaced it with a series of online viewing rooms.