OK -- had version 6.5.4 on my website. Had two problems:
Couldn't turn on recaptcha for entering CC number on Paypal advanced page - error out every time. Turned off recaptcha until I could look at it again.
And
Cancel and return from paypal was throwing error. Never had a fix for this one in 6.5.4.
Fix was in 6.5.5 (if I remember correctly) but I never had time to install this.

Now I have updated to version 6.7. Similar issues.
Customer reporting recaptcha not working. I tried CC with Paypal advanced page - it worked. Seems all other customers used plain paypal for payment so no other reports. He didn't say what went wrong. Turned off recaptcha .. again.

And cancel and return from paypal gives this error:
"PayPal Express Error: Error, couldn't connect to https://api.paypal.com/2.0/ (-2147012852).
A certificate is required to complete client authentication"

Definitely a different error than the 404 error I had earlier experienced with 6.5.4.
So, now what is this error?
I know Paypal advanced is set up correctly - I've been using it for a long time and just used it myself a few hours ago.

And to make things more fun - I cannot verify this on my paypal express setup page on paypal. Seems my old password expired and they won't let me enter new password. Paypal page just tosses an "Error: an error has occurred".

Thanks,
Ed

Hi

It's not possible to use recaptcha with PayPal Advanced (or PayPal Payflow Link) due to the way they operate. You shouldn't get recaptcha showing at all if PayPal Advanced is chosen as a payment method - can you go through your checkout a couple of times and check that is the case as it certainly is here on testing.

Can you let me know the URL so I can check that too and the cancel error you get when using PayPal Express Checkout?

Andy

Please feel free to review / rate our software

OK, recaptcha is not coming up on PP advanced - just as Andy mentioned.
Customer won't tell me what his issue was nor has anybody else had a problem, ignoring that customer's complaint due to lack of information.

2nd error -- error when hitting "Cancel" at paypal payment page.
After finally getting paypal manager login working (had typo in password) -- reviewed setup on Paypal setting page.
All were fine ... except the entry that mattered. For the cancel URL - it had "/cart.asp" on the end. Deleted that and all is happy.

What was the answer to this. We have the same exact same problem today!
Help!

Can you let us know the exact problem as there were 2 or three things in this thread? Which PayPal method are you using?

Andy

Please feel free to review / rate our software

See my other post for answers. Go to 3 page
https://www.ecommercetemplates.com/support/topic.asp?TOPIC_ID=110195

Either we solved the problem or PayPal finally fixed their servers because there are a ton of almost the exact errors we got posted in other webmaster forums.