Hi there! I'm running the latest stable version of Unraid (7.1.4). In the past I've had some trouble booting via USB, but after either booting in safe mode, or trying a new USB port, things seemed to work again... up until recently....

After a power outage a week ago, I was getting a bzmodules checksum error - press ENTER key to reboot

I tried repairing the USB drive in windows, (no errors, and no joy), so I swapped to a new USB stick ( a Verbatim 64G USB 2.0 toughstick), used a recent backup, and was off to the races, or so I thought.

Skip forward to today: The server was behaving strangely this morning (trying to get to command prompt was giving me an nginx error for example), so I tried rebooting, and it won't boot with the bzmodules error again. I've tried booting in safe mode with no luck, as well as swapping the USB port.

I do have an unraid connect backup from this morning, so I'm pretty sure I can rebuild the USB stick, but I'm worried that it is still happening. Any suggestions or advice?

Try recreating the flash drive, first backup the current one, then recreate it using the USB tool, confirm the flash drive boots with the stock install, and if yes, restore only the /config folder from the backup overwriting any existing files, if you get the same issue, recommend running memtest.

Yeah, that’s what I did last time this happened. - it worked but then recurred, which is why I’m reluctant to just do it again - if it keeps recurring that’s not a real fix. Memtest is a good idea - I’ll try that now - thanks.

So, I ran memtest through 2 cycles, and it has passed. I'll try rebuilding the USB drive now.

Since the issue normally indicates a problem reading files from the flash drive then if rewriting the flash drive does not help and since you get the same behaviour with two different flash drives and you do not think you have a RAM issue then it is possible you have a dodgy USB port.