Wont let me log in on national ice cream day!

So the app logged me out while being closed. Then when I opened it up I had to log it. But it has an error code saying, "something went wrong, please try again." No matter how many times I try to log in it gives me the same message.

Then I tried to reset my password, maybe it was something wrong with my username or something. But then it says, "malformed date encountered." I cant use the app to get the free ice cream! Help!

Jusangen about McDonald's, v5.5.1