Diagnostic query: Unexpected kernel panic on macOS Sequoia 15.1 after waking (1794682658)

[Marcus Reed]

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?

[Emily Hart]

Irrelevant to this panic signature. The AppleThunderboltNHI assertion indicates a Thunderbolt controller (NHI) firmware/hardware handshake failure during D3cold exit, not a peripheral pairing issue. Action: Disable “Wake for network access” & “Power Nap” via pmset -a tcpkeepalive 0; pmset -a powernap 0. Force NHI firmware reset: sudo pkill -9 thunderboltd then cold-boot with dock disconnected. Check log show --predicate 'eventMessage contains "AppleThunderboltNHI"' --last 24h for 0xe00002c9 (link training timeout) errors.

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

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

[Claire Bennett]

Irrelevant to this panic signature. Error 4013 is a DFU/restore USB signaling error; this panic is a kernel IOPlatformPluginFamily power state timeout (often kIOPMNotReady or kIOPMAckTimeout) waiting for the TBT NHI to resume. Action: Verify APFS snapshot pressure isn’t blocking the wake path: tmutil listlocalsnapshots / and prune if > 3 exist (tmutil deletelocalsnapshots ). Test with sudo sysctl debug.lowpri_throttle_enabled=0 to rule out throttling starvation during wake indexing. Ensure dock PD contract is stable: system_profiler SPPowerDataType | grep -A 5 "Thunderbolt".

MacBook Pro 16″ M2 Max | iPhone 16 Plus

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

[Owen Parker]

Irrelevant to this panic signature. Liquid detection triggers AppleSMC/ApplePMGR alerts, not AppleThunderboltNHI link-layer assertions. Action: This panic maps to Sequoia 15.1’s known regression in IOThunderboltFamily handling of DisplayPort Alt Mode MST hubs during S0ix exit. CLI: Capture a full panic dump via sudo nvram boot-args="keepsyms=1 -zp -v" and inspect Backtrace for IOThunderboltNHI::completePowerStateChange. Hardware Recovery: Update dock firmware (CalDigit/OWC/Belkin sites). If persistent, disable TBT security temporarily: csrutil authenticated-root disable (Recovery OS) -> nvram boot-args="tbtdisable=1" to isolate NHI vs. DP MST logic.

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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