Bob Weir, a founding member of the Grateful Dead, has suddenly canceled all his upcoming appearances, according to messages posted Sunday on Facebook accounts linked to his various projects.

The cancellations include all shows for the rest of the year with his band Ratdog, as well as a concert with Further, a group that also includes Phil Lesh, another Dead co-founder.

The message doesn’t give a reason for the cancellations:

Identical messages were posted on the Facebook pages of Further and Weir’s TRI Studios.

Futher had only one upcoming show on its schedule, an appearance at the Lockn’ Music Festival in Virginia in September, while Ratdog had numerous dates scheduled for the coming months.

Ratdog took the stage without Weir last month for an appearance in Las Vegas, according to JamBase. A statement from the venue said Weir was “under the weather.”

Weir, 66, also collapsed on stage in April 2013.

The announcement comes a day after the 19th anniversary of the death of Jerry Garcia, another founding member of the Dead. Garcia died of a heart attack on Aug. 9, 1995 after a long battle with addiction and numerous health problems.