How to fix Woo Commerce Square PayPal authentication error?

Question

PayPal

A couple of weeks ago, customer transactions were processed smoothly, and then at some point, transactions began to fail with the message "Authentication failed". I'm using Square and Paypal to collect customer payments on a Wordpress checkout page. Customers who signed up with Paypal are fine (Paypal Checkout option works). However, all customers who have chosen with the Square payment option show that their transactions are not being processed. Please tell me how can I fix this problem so that customers can checkout. The error message displayed in the attached screenshot is the same error message that I get on all attempts at new credit card orders. Earlier today I updated the Woo Commerce Square plugin,