I have an issue with my unraid server after a power failure and I get the firmware checksum error on boot up. I have checked the usb is OK using windows chkdsk and I have changed out the usb stick for a new one but the same problem occurs. What can I do?

Cheers

Maurice

That looks like a flash drive problem. Does a different flash drive using a stock install boot? No key needed, just for testing.

@JorgeB I have the same problem today see picture below, so I should test a new USB first with stock standard if that is ok what would be next move to get my Unraid server back online ?

9 minutes ago, justintas said:

so I should test a new USB first with stock standard if that is ok

sure

@JorgeB it booted correctly with replacement USB so that's good what's next step to get the server back ? Or can you point me in the right direction Cheers Justintas

As a first step I would suggest is recreating the old flash drive, first backup the current one, then recreate it using the USB tool, confirm the server still boots with that flash drive and a stock install, and if yes, restore only the /config folder from the backup overwriting any existing files.

@JorgeB thanks mate, copied config file booted up but have a screen with license info :
Multiple License Keys Present

There are multiple license key files present on your boot device and none of them correspond to this device. Please remove all key files, except the one you want to replace, from the /config directory on your boot device.

Alternately you may purchase a license key for this boot device.

If you want to replace one of your license keys with a new key bound to this device, please first remove all other key files first.

Assume can copy old key or just support Unraid and get a new one ?

You got me out of a jam going to buy you a beer : )

Are you using a new flash drive? If yes, copy only the last bvalid key and then transfer it https://docs.unraid.net/unraid-os/system-administration/maintain-and-update/changing-the-flash-device/#why-replace-your-usb-flash-boot-device

You can also contact support if you prefer or cannot transfer it yourself

On 4/28/2026 at 8:05 AM, mauriceatkinson@btconnect. said:

I have an issue with my unraid server after a power failure and I get the firmware checksum error on boot up.

If you're not using a UPS, you should.

Also, be very selective about the quality of new USB drives.