Maybe there was a recent update to the app itself, or a server-side update, and you are having issues logging in or you are experiencing strange app behavior.
Below are some steps to take to remedy the issue:
Application is locked up and won't respond to touch
Press the Home button two times quickly, in the preview of apps find Astea Mobile and swipe up on the preview to close it. That will force quit the app. Then try re-opening the app.
Sign-in issue or app error message
Perform a switch user, power off the iPad, power it back on, sign back in to Astea Mobile.
Settings > Astea Mobile > Reset App
Now open Astea Mobile and you will have to sign in and input the server address: