If you updated your navigation to the current version and afterwards lost Engine and Info Monitor Function, as well as compass and navigation direction on the instrument cluster, it is not the file that is bad, it was the update.
I updated my 2015 Legacy Limited last year and for the last 8 months thought that the firmware version was bad. Yesterday I tried the update again and it fixed my issue.
Some key notes:
Make sure you use 2GB flash drive formatted FAT32 (It says you can use up to a 4GB drive).
Check your Unit Version Information: When I lost the engine and info monitor function the Nor and ESD were updated to the updated version, but DB was not. If your DB is not updated, then this is a sign that the second USB did not update properly. (also my CAN changed versions too once the second update was successful)
When updating the second USB, the progress bar for me completed three times, I believe for each file on the usb stick. The first time I tried to update it, the file transfer and upload happened very fast, faster than USB 1 (this is also an indicator that the second USB update failed). It should take slightly longer than the first USB.
It seems like the it first transfers the files to the ECU, then once it is complete and you restart the ACC, then it actually installs the update.
I redid both USB 1 and 2 (not sure if you had to redo the 1st one, but I did just in case) and took my time and followed the instructions exactly (sometimes waiting an extra couple of seconds). Hope this helps someone.