Have you tried rebooting the infotainment unit ?. That's a long press on, on / off till the unit reboots. About 10 seconds.
Failing that the card might have got corrupted. Ie. Knackered. They do / can wear out. You would buy an e-seller card and if you didn't have the overall.nds file treat as the lost card one talked about on the thread.
You could try the old fix bad sectors thing of Windows. That's method 1 of this. I've done it on SD cards but not a map card.
If your camera SD card has developed bad sectors, then you are on the verge of losing all your favorite photos, videos, or music stored on it. Bad sectors lead to corruption and consequent data loss. It is frustrating to deal with the problem. Users complain of unsuccessful attempts to...
www.stellarinfo.com
The map card goes in slot 1 btw.
Failing that feels like you need a new card and follow the lost card link in the resource if you don't have the overall.nds file:
This resource is applicable to all Seat navigation systems plus other Vag brands which are MIB2 / 2.5. It is built from the knowledge base on the Leon forum from a long running thread which has the advantage of tracking the twists and turns over...
www.seatcupra.net