I'm having trouble fixing the onepage checkout system. The checkout page buttons don't let you go to the next step, I'm assuming this is the javascript?
In the console it is displaying a few errors but mainly this one:
Uncaught TypeError: Validation is not a constructor
at d.save (opcheckout.js:353)
at HTMLButtonElement.onclick ((index):565)
Best Answer
Please try to add below line into
index.php
Then check the checkout, view source and you will got the current error.