Not sure if anybody else has come across the problem of KTS's injected main.js file causing issues with Wordpress site's Woocommerce plugin for Square. It throws a fit when the site tries to load an iframe (credit card details inputs) on the checkout page. 

I'm pretty convinced that it throws a 499 error from time to time as well, blocking the iframe from showing - although this behaviour is rare.

I have contacted Woocommerce, but they could not provide any help - they suggested turning of KTS's injection. Ok for me but not my customers. 

Any help, greatly appreciated.

Hello, @diafol

Could you try to set a trusted address related to your credit card payment address or the website mask in Network Settings of the Settings of KL product ?

Regards.