Undefined property error

Hi there ??

This kind of problem is usually caused by either a conflict with another plugin. The best way to determine this is to:

1. Disable all plugins except for NexGEN Gallery.
2. Temporarily switch your theme to a WordPress default one like Twenty-Twenty.
3. Repeat the action that is causing the problem

If you’re not seeing the same problem after completing the conflict test, then you know the problem was with the plugins and/or theme you deactivated. To figure out which plugin is causing the problem, reactivate your other plugins one by one, testing after each until you find the one causing conflict.

Before you start

First, please make sure you have a good backup in place of your full site and database. Most hosting companies have this included in the subscription, but you could also consider using a service like Jetpack. If something goes wrong, it’s nice to know that you can restore your site.

Second, I would suggest installing a plugin called Health Check & Troubleshooting. This is a plugin developed by the WordPress community and it allows you to disable plugins without affecting your current site visitors.

Cheers.