Mobile Apps not Accepting Credentials

I'm having an issue where my credentials will not be accepted by any of the apps. I can log into the main website just fine. I logged in and changed my password when this first happened, several months ago, but to no avail; it keeps giving the same "invalid credentials" error.

Please help.

What version of Gospel Library are you running? Based on your screenshot, it looks like you're on Android. Gospel Library 5.7.0 for Android is in beta, and has some fixes for authentication issues. I don't know if it would fix your issue, but it might be worth a try – if you go to the Gospel Library listing in the Google Play Store, and scroll down a bit, there's a link to join the beta.