I also had a lot of problems entering my password. I had to do it twice, and after it said I was successful, it asked for my password again. I hit cancel and then it said, thank you for supporting FlickType.
Once I started typing everything seemed ok, but after I dismissed the keyboard and then went back to type, it asked for my password again. I reverted to build 86 and went back to finish the email, but all of my text was gone.
I started a new email using build 86 and when I moved the cursor back to enter a line of text before the last line I typed, the text I typed last disappeared.
I am using FlickType classic to type this email.