Google home Failed to save devices

i keed getting this when i try to update my google home list

and it does not tell me what the problem is

Hi Richie,

It seems that there are quite a few characters that are not allowed in the Google alias for the devices/scenes. In that case you get a similar message, but the offending entry is also highlighted by a red border. Did you scroll down to see if there are any?

Cheers Rene