Yes, I understand how offline works BUT I cant get past the error message and otherwise blank screen. Ive turned off n on, tried swiping it away just to get to the screen to enter the sale amount. I will try the force quit to see if it will work. Crazy since I have bars. Settings doesnt even have ONlLINE for a choice! Something must be corrupted somehow.  Lost sales, not good. Thanks for responding so quickly.

You're welcome.  I'll suggest a few things even though you may have already done them.  Have you tried deleting the App, then restoring it?  Is your device's (phone or tablet, I assume) software up to date, and have you tried powering it down then back up again?  Do you have a second device you could try it on?