Yes, but it's not this easy - you could kill the KPA in case you don't know what you do - but in my case - it was unusable already
I played with a lot of different key combinations - there is a 'Maintenance Mode' hidden in the KPA - but it seams not to work with the latest beta anymore ...
But I found a way to load an old firmware version - with the Maintenance mode included.
Update:
I created a small website with some of my findings:
http://www.soundside.de/support/KPARecovery.htm
Here is what helped with the old firmware:
01.) Switch off the KPA
02.) Put old Firmware (6911) in root (!) directory of USB stick
03.) Hold (both) < Page > and turn KPA on to tuner
04.) Booting and burning from USB device - KPA starts several times - wait
05.) The same error message appears since there is junk in the profiles/rig storage
06.) Switch KPA off
07.) Hold the left/top soft-key above the LCD - turn KPA on to tuner
08.) Maintenance Module will be started
09.) In the 'Test' menu a lot can be tested (buttons, knobs, led, memory, ...)
10.) In the 'Maintenance' menu there is 'Memory' and 'Rig' available - I use Memory FormatFlash and InitFlash
11.) Normal restart (without the USB stick)
12.) It started normal - tuner works fine - but NO rigs in the KPA - all empty
13.) Put my USB Stick inside - loaded my old backup and ... all the same errors - so for whatever reason the backup is corrupted
14.) Did all again but not reloading my backup (Skip step 13)
15.) Imported all my single rigs (it's a good idea to export all rigs from time to time - in addition to backup)
16.) It takes some time ....
17.) KPA reports 'successfully imported 424 files')
18.) press ok - KPA reboots
19.) Everything works fine - stock and my own profiles/rigs
20.) I lost my input settings (for all my guitars) and the system settings (like KPA Name...) but that's ok
Again - read all here carefully and don't complain in case it does not work - do not play with any of these settings 'just for fun' in case your KPA works fine.