I’m running macOS 26 Beta 1 (build 25A5279m) on a 2019 Mac Pro (MacPro7,1) with a single 4K display connected via HDMI. Whenever I attempt to launch Finder, WindowServer immediately aborts and the machine reboots.
Crash details:
Process: WindowServer (PID 1441)
Exception: EXC_CRASH (SIGABRT) triggered in thread 0 (ws_main_thread)
Termination Reason: Abort trap: 6
Backtrace highlights:
CA::OGL::MetalContext::draw(MTLPrimitiveType, …) hits an internal __assert_rtn in libsystem_c.dylib
Subsequent calls all stem from QuartzCore’s OpenGL/Metal bridge (CA::OGL::render_layers, LayerNode::apply, etc.)
Related threads:
Thread 2 (com.apple.coreanimation.render-server) idle in mach_msg_overwrite
Thread 1 shows AmbientDisplay and ColorSync callbacks running
Hardware/Software:
MacPro7,1 (2019)
macOS 26.0 Beta 1 (25A5279m)
4K monitor via HDMI
System Integrity Protection enabled
What I’ve tried so far:
-
Safe-boot (crash still occurs)
-
Switching display profiles in System Settings → Displays → Color (no effect)
Happy to provide any additional logs or verbose console output. Let me know if there’s any other data that would help diagnose the Metal/OpenGL integration issue in this beta.