Everything indicates that there was an error in the update or that you mistakenly selected an update for which you don't have a licence.
The Snooper contains a serial number for the software and on the SD card, you can edit this serial number on the SD card, but if you don't have a backup copy of the old or current original software, it's useless to edit the serial number.
If you want to try installing new navigation software, for example iGO Primo, you can try the following (I don't know if it works on the 6900 model):
Keep the original SD card or make a backup copy of the SD card and save it on your PC (if you make a backup copy, make sure it contains the serial file).
I recommend leaving the original SD aside and trying a new SD card with 8 GB or less storage capacity, placing the "asimap" folder on the new SD card.
Switch on the GPS and if a file explorer appears, you can install other navigation software.
Spoiler: attached
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