Yup, same on 2130s. I see notes about the app going to a Yahoo address. Yahoo is probably offline. Users are complaining over in the Grandstream forum.
I found that they did a API update and it broke it. Posted it on the Grandstream forum but no answers for a ETA.
I assumed this would require a firmware update. Always a dangerous thing. There’s a beta up but I don’t think it fixes this.
Do you think rolling back to an older firmware would fix the phone?
I doubt it. The error appears to be upstream, meaning Yahoo or whomever Grandstream is drawing their data from. They changed their API. So until Grandstream changes how they access the data we are out of luck.