Doesnt Work

I downloaded this app because I need to fly on United several times in the coming month but it will not let me log in. I constantly get an error message with no details. I can log onto the website and it works fine but i travel all the time and live on my phone. I need this to work so I get my boarding passes, check flights, and book additional flights. How can a major airline have an app this bad? I hope their plans have better maintenance than their apps. My Southwest, Delta, and American apps all work.

DRM913 about United Airlines, v2.1.13