Diagnostic query: Unexpected kernel panic on macOS Sequoia 15.1 after waking (1794492435)

[Nina Patel]

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?

[Claire Bennett]

The AppleThunderboltNHI assertion during wake strongly suggests a Thunderbolt/USB4 retimer or PD controller firmware desync after the Sequoia 15.1 bridgeOS update; Error 4013/9 analogs appear in log show --predicate 'subsystem == "com.apple.iokit.IOThunderboltFamily"' --last 24h as kIOUSBHostPortPowerChange storms. Disconnect all downstream TBT/DP devices, then force a cold-reinit of the TBT controller via sudo pkill -9 usbd; sudo kextunload -b com.apple.iokit.IOThunderboltNHI && sudo kextload -b com.apple.iokit.IOThunderboltNHI while on AC power. If the panic recurs, capture a sysdiagnose immediately post-wake and check IOPlatformPluginFamily timestamps against ApplePMGR thermal assertions — this isolates whether the dock’s PD 3.0 PPS handshake is stalling the CPU C-state exit.

MacBook Pro 16″ M2 Max | iPhone 16 Plus

London, UK | "Swap the USB-C cable before blaming the logic board."

[Owen Parker]

Intermittent IOPlatformPluginFamily panics with AppleThunderboltNHI backtraces often mask AppleSMC liquid-detection interrupts (LCI) on the TBT/USB-C flex assembly; run log show --predicate 'eventMessage contains "liquid" or eventMessage contains "LCI"' --last 7d to surface hidden kIOLiquidDetectionAsserted events that throttle the SoC and corrupt NHI state on wake. On cellular-capable Macs, a stuck com.apple.CommCenter eSIM provisioning daemon can hold a PreventUserIdleSystemSleep assertion — verify with pmset -g assertions | grep -i commcenter and reset via sudo launchctl kickstart -k system/com.apple.CommCenter. Finally, validate the VRM thermal sensors (istats scan or sudo powermetrics --samplers smc -n 1 -i 1000) for TH0P/TC0P deltas >15°C during wake, indicating a failed thermal-paste bond on the TBT retimer BGA.

iPhone 14 Pro | Apple Watch Series 10 | MagSafe Duo

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

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