panic(cpu 2 caller 0xffffff7f987f6ad5): userspace watchdog timeout: no successful checkins from com.apple.WindowServer in 120 seconds service: com.apple.logd, total successful checkins since load (2030 seconds ago): 204, last successful checkin: 0 seconds ago service: com.apple.WindowServer, total successful checkins since load (2000 seconds ago): 188, last successful checkin: 120 secon