No web-access

Now i have done a 40-sec reset. No change. Except now i can’t get the device to save my email adress in the “User Profile”: I type in my email but when it tries to save it i get an error:

This email account cannot be deleted. Make sure your device is
registered and your network connection is functioning properly, and then
try again. (250010)

I also tried to change the router DNS, as was suggested in a different thread (here) but no change.