I am having the same issue. I am still working with tech support but the issue is not resolved yet and I haven’t heard from them since I provided information they requested a day and a half ago, so hoping they haven’t lost track of my issue.
We have a licensed version. Users make payments using the PayPal add-on but the form gets stuck “processing” when returning from PayPal. Therefore no screen confirmation shows and no notification emails are sent.
The only time it works is when I am logged in to site and run the form in preview mode. When I run the form in page mode it gets stuck whether I am logged into site admin or not.
We have tested with 2 different browsers, cleared history, purged cache, followed the protocol disabling all plugins, changing theme to Twenty-X etc. Have run in sandbox and live, and provided error logs.
Ninja Forms – Addon Manager by The WP Ninjas version 3.0.13,
Ninja Forms – Conditional Logic by The WP Ninjas version 3.0.22,
Ninja Forms – Excel Export by Hannes Etzelstorfer version 3.3.1,
Ninja Forms – Multi-Part Forms by The WP Ninjas version 3.0.24,
Ninja Forms – PayPal Express by The WP Ninjas version 3.0.14,
Ninja Forms – Layout & Styles by The WP Ninjas version 3.0.25,
Ninja Forms – File Uploads by The WP Ninjas version 3.0.20,
Ninja Forms by The WP Ninjas version 3.3.17
WP Version: 4.9.8 – Supported
WP Multisite Enabled: No
Web Server Info: Apache
PHP Version: 7.1.1
MySQL Version: 5.6.41
It looks like this has been an ongoing problem. Can this be resolved? Would upgrading the php version to 7.2 make a difference?