Mac crashing when Hard drive plugged in (Mac)

May be an issue with the file system on the drive or even the partition table.

Or there may be a hardware issue with the external drive or cable, or any adapters, docks, hubs being used. Or there may be an issue with the laptop's USB port. Try using another USB port especially on the other side of the laptop and try connecting the drive directly to the laptop. Try using another cable/adapter. Also disconnect all other external devices in case one of them is causing a problem.

If you have access to another Mac, then try connecting the drive to that computer to see what happens. Hopefully the other Mac is using an older version of macOS since macOS Monterey seems to have all sorts of odd quirks these days and doesn't play as nicely if something odd is encountered. But testing the drive with another Mac may tell you if the issue is with the laptop or the drive/cable/adapter. If the drive mounts try running Disk Utility First Aid on the volume, on the hidden Container, and even on the physical drive since the problem may be with the partition table.

You can also try powering off the laptop & trying to boot the laptop with the external drive already connected to see what happens.

You can also try booting into Safe Mode in case you may have some third party software installed that is interfering with the normal operation of macOS.

jørgen35 wrote:

Thanks! I have tried the drive on multiple systems, they also crashes. Therefore i belive it is the drives fault. Do you know how i could fix some of these: "issue with the file system on the drive or even the partition table. "?

Unfortunately if it is crashing every system, then you may not be able to do anything yourself. Maybe try connecting the drive through a USB3 hub. Maybe the hub will act as a bit of a filter -- this is a long shot.

There is a chance the drive's enclosure is causing a problem. It used to be possible to remove the actual drive from an enclosure to connect it to another drive enclosure, drive dock, or USB to SATA Adapter, but these days many USB drives have the I/O ports & USB controller integrated directly into the drive's main board. Plus some enclosures are glued together these days and not meant to be disassembled.

Otherwise, if you need to recover data from the drive, then you will most likely need to contact a professional data recovery service such as Drive Savers. They provide free estimates and are recommended by Apple and other OEMs.

If you don't need data from the drive, then you could try connecting the drive to a Windows or Linux PC to try erasing the drive, then trying to connect the drive to the Mac so you can use Disk Utility to erase the drive.

Hey there! Considering it happens on multiple machines, I would suggest saving the data on that drive to another, (If you need the data and don’t have it elsewhere), then erasing or reformatting this external drive:

Erase and reformat a storage device in Disk Utility on Mac - Apple Support

Although it maybe a good idea to test on this first, with another port/chord/external drive just to be sure where the problem lays!

How about other ports, other chords? (I know you have already tried other computers). And likewise if you’re using some adapter or hub how it responds? If all fails, the hardware on your external drive has probably failed. Hope that’s not the case though! Some external storage companies provide data recovery services, depending. Hope it works out!

Good job. macOS in Recovery Mode is much more limited which may be why you were able to successfully connect the drive this way. Thanks for following up.