I haven't used the card reader since last year (I think it worked ok then) and needed it for an event this weekend.
The card reader was charged and showing the green light, the App was open on my phone but when I went to Checkout and inserted the card nothing happened.
I was able to manually enter the card details and complete the sales but reading the card would have been preferable (we get charged a higher rate do we not for manual entry?).
What can I do to prevent this in the future?