One of my vendors says the Paypal payment is not secure and will not load on their computer

I created a form with payment option using paypal. A vendor attempted to pay and stated 

The link to pay via Pay Pal is not secure and will not load on my computer. Any other methods for credit card payments available?

Is there a way to make it secured or options to help?

The form is secure and will always open with HTTPS on the URL. Would you mind asking the vendor to provide a screenshot of the error they're getting? Perhaps, it is there Anti Virus or security settings that are blocking Jotform, so it is not related to the form, but to their computer.

We have Stripe, Square, Authorize.net that offers credit card payment.

I will email the vendor and attempt to get a screen shot.

It must be the Firewall settings, Antivirus, the browser extension that could cause the issue. Could you please ask the user to check these settings on his end.

We are waiting for the response.

Thanks.

It must be the Firewall settings, Antivirus, the browser extension that could cause the issue. Could you please ask the user to check these settings on his end.

We are waiting for the response.

Thanks.