After years of successful usage and map updating this message was displayed after another update, and now remains displayed no matter what I do (delete/repair corrupted map, smaller map..). Also after recovery of the system (hold on/off-button until 'small text displayed'and then '3x on/off-button within one second': system being recovered). All routines have been tried a dozen times without result (sometimes interrupted by "servers busy, try again later" but also several times 1"00% downloaded" but "some items not updated").
A check on serial number says "Your device is fully supported". What else can I try?