[19-Jul-2016 02:49:48 UTC] PHP Fatal error: Cannot redeclare class OAuthException in /home6/hemptsyc/public_html/wp-content/plugins/wc-vendors/classes/gateways/PayPal_Masspay/api/lib/auth/PPAuth.php on line 0
Boom. There’s the issue. Let’s debug it section by section:
PHP Fatal error – This means your website will crash when this error occurs, as opposed to a warning or a notice which you can generally ignore.
Cannot redeclare class OAuthException in........ — This tells you that another plugin is trying to load PayPal’s Mass Pay API at the same time WC Vendors is. This means you have two plugins installed and activated that are doing the same thing and conflicting with each other.
This is why, before submitting a post, you’re instructed to disable all other plugins, and test. Had you done that, you would have seen this is a plugin conflict, and that the resolution is to use only one paypalap plugin, the one that comes with WC Vendors. 🙂