Paypal payments not going through/being recognized

Hi,

I setup a paypal button through the plugin and put it on my site but when users go in and pay through paypal the payments aren’t being picked up by the site/plugin. The payment is going through, I’m receiving an email from paypal and the user is also receiving an email from paypal but the payment isn’t showing up in the “Payments” section of the plugin nor is any email from the plugin being sent for the users to register. I have IPN enabled in Paypal. Below is the IPN notification that I’m seeing in paypal.

Instant Payment Notification (IPN) details
Back to IPN History
Message ID
5A926503TT276305J
Date/time created
1/15/2017 19:11 EST
Original/Resent
Original
Latest delivery attempt date/time
1/16/2017 06:34 EST
Notification URL
http://somebodyelsesmoney.com/demo/?swpm_process_ipn=1
HTTP response code
What’s this?
500
Delivery status
Retrying
No. of retries
13
Transaction ID
IPN type
Recurring payment profile

txn_type=subscr_signup&subscr_id=I-UTVGYMN1VVWF&last_name=Byrnes&residence_country=US&mc_currency=USD&item_name=PayPal&business=chris@howlingwolf.org&amount3=1.00&recurring=1&verify_sign=A301WH.m-LRZBgqQP6aRD2T8A9xVAKAzn0knpqb8uMSunagWJhrHLnwj&payer_status=verified&payer_email=cbyrnes8@gmail.com&first_name=Christine&receiver_email=chris@howlingwolf.org&payer_id=VGJXZL87YZFKL&reattempt=1&item_number=1011&subscr_date=16:11:32 Jan 15, 2017 PST&custom=subsc_ref=2&user_ip=67.242.16.242&charset=windows-1252&notify_version=3.8&period3=1 Y&mc_amount3=1.00&ipn_track_id=e02fe6253eddd

Please advise what I need to do.