If you or one of the users of your company experience issues logging into the app on your tablets please perform the following actions: 

Make sure:

1. That your tablet is online (logging in to the app is not possible when you are offline). Once you login while online, you can of course continue to use the app while offline because you will remain logged in.
2. That you have an updated version of the app by going to the relevant App store and checking if you need to update the app. 

If the error message is invalid credentials — check your login details!  

If the app is crashing during the login — delete the app and download it again from the relevant App store.