Late 2017 iMac 27" booting from external SSD experiencing panics

Late 2017 iMac 27" (18,3)

Ventura 13.7.8, 40GB RAM

with 27" Thunderbolt Display connected via Apple Thunderbolt adapter

Booting from an external 2TB OWC Envoy Pro FX via Thunderbolt 3


Experiencing panics on waking from sleep and restarting... this doesn't happen every time, but it's become more of an issue in the last couple of months. It has happened a couple of times during use, but by and large it's been happening on wake.


Backstory: The original internal Fusion drive (still connected and running with nothing stored on it) started really slowing down and getting flaky after about 4 years, a problem that seems to be well-documented with these drives. Being that I liked my setup with the 27" Thunderbolt Display and didn't want to dump a large amount of cash to upgrade, I opted for a 2TB OWC external SSD to breathe new life into the old guy. This has worked amazingly well for the first 10 months or so, then I started experiencing these occasional panics which are becoming more frequent over the last couple of months.


As an attempt to narrow the trigger down, I tried changing Energy Saver settings so as to disallow sleep with the screen saver kicking in at 15 minutes, but it crashed and restarted when coming out of the screen saver after an hour or so.


It was suggested elsewhere to reset PRAM which I've done along with an SMC reset, and I thought that might have helped as I didn't see a crash for a bit over 2 days, but today while streaming audio, it went down and restarted.


It's also been suggested that leaving the failing Fusion drive in the iMac could be causing the problem, but I haven't looked into that yet.


Hoping someone can shed some light on my issue. Most recent panic reports as well as an Etrecheck report below.


Posted on Feb 10, 2026 1:02 PM

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Feb 10, 2026 1:34 PM in response to sluggo

Start by uninstalling both of your third party anti-virus applications; Surfshark and Crowdstrike. These are not needed and the application type often cause problems and conflict with the correct operation of the OS.


Apple has built XProtect anti-virus technology into macOS and keeps it updated regularly.  Who better know’s how to protect your Mac and macOS than Apple?

Protecting against malware in macOS - Apple Support 


Also uninstall any VPN apps that you have, unless they are specifically required by your bank, employer or education entity.

Private VPN's are Anything But Private and 

Security Risks: The Dangers of Using Free VPNs – eccu.edu.  


Uninstall these, reboot the Mac and reevaluate the problem for a little while.

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Late 2017 iMac 27" booting from external SSD experiencing panics

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