Diagnostic query: Unexpected kernel panic on macOS Sequoia 15.1 after waking (1794486312)

[Daniel Hayes]

Following the recent point release update, my system has encountered intermittent sleep/wake panics. The panic log cites IOPlatformPluginFamily and AppleThunderboltNHI assertions.

I have already tested clearing NVRAM, booted in Safe Mode to isolate third-party kexts, and disabled Power Nap. Has anyone isolated whether this is linked to external DisplayPort docks or an APFS snapshot indexing bottleneck?

[Owen Parker]

Check log show --predicate 'eventMessage contains "liquid"' --last 7d for any AppleSMC or IOHIDSystem liquid intrusion events that trigger silent thermal throttling on wake, as the IOPlatformPluginFamily panic often masks a THERMAL_LEVEL_CRITICAL assertion caused by corrupted sensor calibration post-liquid exposure. If the Mac supports cellular (e.g., iPad Pro logic board in a Mac chassis or specific prototypes), reset the eSIM modem firmware via cfgutil or Apple Configurator 2 to clear stuck AppleThunderboltNHI power domain handoffs during resume. Verify the AppleSMC thermal sensor keys (TC0C, TCGC, THSP) in ioreg -lw0 | grep -i temperature match expected deltas; a stuck THSP (Sleep) sensor will force the PMU to assert a panic rather than resume a thermally unknown state.

iPhone 14 Pro | Apple Watch Series 10 | MagSafe Duo

Denver, CO | "Let humid USB-C ports air dry — never reach for rice."

[Ethan Carter]

Investigate photolibraryd and cloudphotod hold on the APFS snapshot via fs_usage -f filesys | grep snapshot during wake, as aggressive “Optimize Mac Storage” eviction races the AppleThunderboltNHI DMA re-initialization, causing a vm_page_fault in the IOPlatformPluginFamily power path. Disable “Optimize Mac Storage” temporarily and force a local library repair (Option+Command launch Photos) to flatten the filesystem metadata load on wake. Correlate bluetoothd crashes in log show --predicate 'process == "bluetoothd"' --last 24h with the panic timestamp; a malformed HCI command packet from a waking peripheral can wedge the IOBluetoothHostControllerUSBTransport, which shares the XHC/NHI power rail, triggering the observed assertion.

iPhone 16 Pro Max | AirPods Max USB-C

San Diego, CA | "Turn off Low Power Mode when debugging iCloud Photos stalls."

[Emily Hart]

Unpair the Apple Watch via Watch.app > All Watches > Info > Unpair to eliminate the com.apple.watchd Nearby/Continuity daemon’s aggressive IOPMrootDomain wake requests that collide with AppleThunderboltNHI link training on resume. If using Universal Control/Stage Manager with an iPad, disable “Cursor and Keyboard” sharing in System Settings > Displays > Advanced, as the AirPlayReceiver service maintains a persistent IOThunderboltSwitch path that prevents the NHI from entering D3cold, corrupting the ACPI _WAK method context. Validate battery health via system_profiler SPPowerDataType | grep -A 5 "Health Information"; a PermanentFailure flag or CycleCount > 1000 with MaxCapacity < 80% forces AppleSmartBatteryManager to request an emergency IOPlatformPluginFamily shutdown during the wake voltage ramp, mislogged as an NHI assertion.

iPad Pro 13″ M4 | Apple Watch Ultra 2 | iPhone 15 Pro

Toronto, ON | "Battery cycle count beats random percentage guesses."

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