I have recently run into a problem with a WordPress site. The problem was the PayPal payment portal button would not show and all that came up was an error like this:
Fatal error: Cannot redeclare class PaymentGateway in /
Read more: Cannot redeclare class fatal error
This problem is being caused by a conflict between the 2 plugins supporting PayPal. I did seem to find a solution though.
In the plugin folder /wp-content/plugins/event-espresso.3.1.12.P/gateways/paypal/
You will see 5 or 6 files. The important ones are these:
Go through these files and rename all Paypal values to another name. The best way is to open something like textpad and do a search for Paypal and replace with new class.
Make sure not to change any of the $paypal_settings or $myPaypal names though.
Be sure to back up all 3 of these files before editing or trying anything. If all else fails contact EventEspresso for support or you can hire me to help you.
Either way good luck and hope this helps.
Thanks to Bill Chambers for help with this