My device:

TomTom One XXL 9.510 (Device capacity=3.62 GB)
Which originally came with this map installed:
United_States_2GB-915.5074


I've successfully upgraded the original map in the past with these maps as they were released:
United_States_2GB_995_8508
United_States_2GB v1005.8764
United_States_2GB v1010.8889


Installed this new one recently:
United_States_2GB v1020.9245

(Meta:
;United_States_2GB v1020.9245
44 1D 9D FD 18 8A EE E1 B3 C4 13 39 8A 9F A2 28 United_States_2GB-101768.meta)


But getting this error message:
"Problem with map
You cannot use this map on this device: United_States_2G-2GB-101768"


I'm thinking I chose an incorrect # 1020 map? Anyone have any ideas please??? Thank you and Merry Christmas

I have already given you an answer somewhere else

I can see that pe1agp is already helping you but just out of curiosity, doesn't the following process work?

viewtopic.php?p=171350#p171350