OMP Paypal Plugin

Dear all,

We are setting up the Paypal plug-in over an OMP site (Version available at, however we can not make it works.

Here the steps we have done:

In paypal:

  1. We created a business account in Paypal
  2. We activated the Instant Payment Notifications as follows:


  1. We activated the Paypal plugin
  2. We entered the email of the Paypal account and the IPN URL, as follows:

After that, we tried to buy a book with other Paypal account (example:, then we checked-out in Paypal , but there is not possible to complete the transaction. Here the message that we received:

Finally, when we click on the button “Return to Merchant” OMP crashes, and prompt the following message and this URL

Fatal error: Call to undefined method PayPalPlugin::getAuthorizedContextObject() in /home/musacomco/ on line 446

I would really appreciate if anyone can tell us how to resolve this issue.

Best regards,

Hi @asoto,

The problem with the “cancel” button can be fixed by applying the patch here:

(There are several different patches listed, but they’re all identical – these are for different branches of OMP and any one would do just fine.)

For the rest of the problem – payments not being processed by PayPal – I’d suggest checking your server’s error log to see if there are any errors related to the PayPal IPN service. If I recall correctly there’s also a way to check on the status of these IPN requests from Paypal within your PayPal account.

And note that PayPal has recently made some changes to its use of encryption, which might need you to check that they’re supported on your server’s PHP implementation. See PayPal and Its Impending Changes to the IPN - WEBii
for some details.

Alec Smecher
Public Knowledge Project Team

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