Bob Weir, one of the founding members of the Grateful Dead, has cancelled all of his upcoming concerts with his bands for an unknown reason. The guitarist, 66, had tour dates scheduled through January 2015 and all have been cancelled.

The news was confirmed on his band Ratdog’s Facebook page. “Circumstances have necessitated that all scheduled tour dates for Bob Weir & RatDog are being cancelled,” the statement read, noting that all shows from Aug. 14 in Boston through Sept. 14 in Nashville were all cancelled. An appearance in Jamaica in January 2015 will also not happen.

According to The Huffington Post, the news was also posted on Facebook pages for the band Furthur and Weir’s TRI Studios.

Furthur is a group that also includes fellow original Dead member Phil Lesh. While performing with the group in April 2013, Weir collapsed on stage and a tour was cancelled. The group went on hiatus this year, but did have a date scheduled at Virginia’s Lockin’ Music Festival.

Ratdog did perform in Las Vegas last month without Weir, who was “under the weather,” the band said at the time.