the app. keeps saying loading.

just says loading on my phone and on my computer it says invalid code?

Are you able to sign in on the app or is it stuck even before that? You might need to force quit or even reinstall if you're having trouble. I'm not sure what code you're referring to on your computer. You should be able to sign in at squareup.com to view your account, but you'll need to use the app to record sales and accept payments. 

I'm having issue where my square the first time plugged in said it was updating it and then it failed.  Now when I try to plug it in it says its reading the square as plugged in but it's not showing up in connected hardware and it isn't working when i try to scan a card. Any ideas? I'm already on my second with same issue. so now i feel its user error.

@corephysique Sorry to hear about that trouble! Here are a few tips that should help you get back up and running: 

- Make sure that your device has the latest version of the Square App.

- Restart your device. 

- Force your reader to restart by using a bobby pin, pen cap, or paper clip to firmly press and hold the button on the reader for 20 seconds.

If these steps don't fix your reader, shoot our Support Team an email and they can help out! If you have any trouble reaching them, check out this thread.

Are you referring to the chip reader? Make sure it's charged. It will show up as having been plugged in even if the battery is dead, but it won't show up as a chip reader unless it's charged.

my reader doesn't work 

@vhclimo we're going to need more info on your issue and device and what type of reader if you want some help.

@jeannettenh You'll just need to download the Square Register App!