Sign In Error. I'm concerned about losing my progress!

Hi, I am new to Grasshopper and till now my experience using this app is also good.
I’m having one slight problem. I already have a Grasshopper account, but yet unable to sign in through the app.
Whenever I try to sign in, there comes a message “Failed to sign in (no user) : A non-recoverable sign in failure occurred”

I’m pretty much concerned about losing my progress so please help me out.