1. Brand new metal Sandisk 32GB USB key, used the USB Flash creator tool on Mac with no issues. UEFI may have been enabled. Server errored out with USB not bootable.
2. On PC, tried to reformat and reinstall OS to USB via PC Flash creator tool. Hit this known Unraid issue from 2 yrs ago, with USB device (incompatible).
3. Followed suggestion on above page to use manual install.
4. For manual install on Windows, downloaded Unraid.zip and verified MD5. Formatted USB drive as FAT32 with name UNRAID. Ran script and received the following error:

5. Quote

   Make Bootable v1.5

   ERROR - syslinux executable not found, expected: C:\syslinux\syslinux.exe

   Press any key to continue . . .

    

6. For manual install on Mac, downloaded Unraid.zip and verified MD5. Formatted USB drive as FAT32 with name UNRAID. Ran script and received the following error: 

   $ /Users/XXX/Downloads/unRAIDServer-6.12.8-x86_64/make_bootable_mac ; exit;
   INFO: make_bootable_mac v1.3
   
   INFO: The following drive appears to be the unRAID USB Flash drive: 
   /dev/disk5
    30.8GB
   
   Permit UEFI boot mode [Y/N]: n
   cp: /Volumes/UNRAID/syslinux/*: No such file or directory
   To continue please enter your admin Password:
   sudo: /tmp/UNRAID/syslinux/make_bootable_mac.sh: command not found
   logout
   
   Saving session...
   ...copying shared history...
   ...saving history...truncating history files...
   ...completed.
   Deleting expired sessions...1 completed.
   
   [Process completed]

   Please advise

 

For Mac manual install, looks like it's failing in the last lines of the script:

mkdir -p /tmp/UNRAID/syslinux ; cp -rp /Volumes/UNRAID/syslinux/* /tmp/UNRAID/syslinux

echo -n "To continue please enter your admin "
sudo /tmp/UNRAID/syslinux/make_bootable_mac.sh $TARGET

 

Try this procedure:

 

    https://docs.unraid.net/unraid-os/getting-started/manual-install-method/

Thanks. I tried manual install from both Mac and Windows with the errors detailed in OP. Mac USB Flash creator tool with deselected UEFI worked. Mac USB creator docs should include a link to open app from unidentified developer.

Edited March 1, 20242 yr by Bladedude

26 minutes ago, Bladedude said:

I tried manual install from both Mac and Windows with the errors detailed in OP.

Looking at the Windows error it looks as if you did not switch the flash drive before running the make-bootable.bat file as that is where the syslinux.exe file is located.

1 minute ago, itimpi said:

it looks as if you did not switch the flash drive before

I don't follow

1 minute ago, Bladedude said:

I don't follow

The error message indicates that the batch file was looking for the syslinux.exe on the C drive - not the flash drive.  Normally if you run the file by right-clicking and then selecting "Run as Administrator" the flash drive will be the current drive within the batch file.

 

Ah gotcha. It wasn't crystal clear from the docs. 

Quote

7. Browse to the USB flash device to see the newly extracted contents from your Mac or PC.

I did that. Files were there.

Perhaps for clarity, it should say browse to the USB flash device, and complete the following steps from the flash device directory.