Error message, but not fields highlighted.

I've looked through the posts on here and I can't find anything that addresses this issue.

I've created a donation form that uses the PayPal Pro add-on, when the PayPal feed is enabled, the form will not submit to PayPal and displays this error "There was a problem with your submission. Errors have been highlighted below." However, there are no fields highlighted and I cannot find any problems with the form. When I remove the PayPal feed the form works properly. I've looked in the Developer console on Chrome and I can't find any issues there either.

The problematic form can be found at http://www.aalove.org/donate/

The site is running Gravity Forms 1.7.6 and WordPress 3.5.2

Any help would be much appreciated.

Thanks for the fast response, I did this and made an attempt. I'm not sure why it's having so much trouble. I do not have a Credit Card form installed on the form, if that matters for this.

2013-07-08 13:06:42 - DEBUG --> Sending one time payment.
2013-07-08 13:06:42 - DEBUG --> Sending request to PayPal - URL: https://api-3t.paypal.com/nvp Request: METHOD=DoDirectPayment&VERSION=52.0&PWD=LX7YTFKTX73EYZL4&USER=shelle650_api1.hotmail.com&SIGNATURE=AFcWxV21C7fd0v3bYYYRCpSSRl31AG8Ccl..sNlUv98Pw97SvcZG9Qiz&CREDITCARDTYPE=&ACCT=&EXPDATE=&CVV2=&STREET=P.O.+Box+101&STREET2=&CITY=Bettendorf&STATE=Iowa&ZIP=52722&COUNTRYCODE=US&CURRENCYCODE=USD&FIRSTNAME=Jason&LASTNAME=Howell&EMAIL=jason%40qctotaltech.com&DESC=&L_NAME0=Donation+Amount&L_DESC0=Donation+Amount&L_AMT0=1&L_NUMBER0=1&L_QTY0=1&PAYMENTACTION=Sale&IPADDRESS=173.23.251.42&RETURNFMFDETAILS=1&BUTTONSOURCE=gravityforms&AMT=1&NOTIFYURL=http%3A%2F%2Fwww.aalove.org%2F%3Fpage%3Dgf_paypalpro_ipn
2013-07-08 13:06:43 - DEBUG --> Response from PayPal: TIMESTAMP=2013%2d07%2d08T18%3a06%3a42Z&CORRELATIONID=d9bd28a2dc5e8&ACK=Failure&VERSION=52%2e0&BUILD=6680107&L_ERRORCODE0=10527&L_ERRORCODE1=10563&L_ERRORCODE2=10562&L_ERRORCODE3=81234&L_SHORTMESSAGE0=Invalid%20Data&L_SHORTMESSAGE1=Invalid%20Data&L_SHORTMESSAGE2=Invalid%20Data&L_SHORTMESSAGE3=Invalid%20Parameter&L_LONGMESSAGE0=This%20transaction%20cannot%20be%20processed%2e%20Please%20enter%20a%20valid%20credit%20card%20number%20and%20type%2e&L_LONGMESSAGE1=This%20transaction%20cannot%20be%20processed%2e%20Please%20enter%20a%20valid%20credit%20card%20expiration%20month%2e&L_LONGMESSAGE2=This%20transaction%20cannot%20be%20processed%2e%20Please%20enter%20a%20valid%20credit%20card%20expiration%20year%2e&L_LONGMESSAGE3=ExpDate%20%3a%20Invalid%20Parameter&L_SEVERITYCODE0=Error&L_SEVERITYCODE1=Error&L_SEVERITYCODE2=Error&L_SEVERITYCODE3=Error
2013-07-08 13:06:43 - DEBUG --> Friendly view of response: Array
(
[TIMESTAMP] => 2013-07-08T18:06:42Z
[CORRELATIONID] => d9bd28a2dc5e8
[ACK] => Failure
[VERSION] => 52.0
[BUILD] => 6680107
[L_ERRORCODE0] => 10527
[L_ERRORCODE1] => 10563
[L_ERRORCODE2] => 10562
[L_ERRORCODE3] => 81234
[L_SHORTMESSAGE0] => Invalid Data
[L_SHORTMESSAGE1] => Invalid Data
[L_SHORTMESSAGE2] => Invalid Data
[L_SHORTMESSAGE3] => Invalid Parameter
[L_LONGMESSAGE0] => This transaction cannot be processed. Please enter a valid credit card number and type.
[L_LONGMESSAGE1] => This transaction cannot be processed. Please enter a valid credit card expiration month.
[L_LONGMESSAGE2] => This transaction cannot be processed. Please enter a valid credit card expiration year.
[L_LONGMESSAGE3] => ExpDate : Invalid Parameter
[L_SEVERITYCODE0] => Error
[L_SEVERITYCODE1] => Error
[L_SEVERITYCODE2] => Error
[L_SEVERITYCODE3] => Error
)

2013-07-08 13:06:43 - ERROR --> Payment was NOT successful.
2013-07-08 13:06:43 - DEBUG --> Validation result - Error code: 10527 Message: <!-- Payment Error: 10527 -->There was an error processing your credit card. Please verify the information and try again.

Thank you so much!