Client's being unable to enter credit card details

Hi there

I've had a few clients say that they've completed my form but been unable to enter the credit card details.  I've tested my form with my cc details without an issue - is there anything you can suggest we get them to look at (like available balance or something?) or do I need them to get me a screenshot of the error?

I checked your Stripe's payment configuration and it's all good. I don't see any problem. If possible, please let us know the exact error they've encountered so we can further investigate. If you have also embedded the form in your website, please let us know the website URL so we can also check it on our browser.