Unknown column 'system' in 'field list'

Problem

Either of these error messages appear somewhere on your website:

Unknown column 'system' in 'field list'

Key column 'system' doesn't exists in table

Cause

This error message appears when older PHP file codes are running on your website, which usually happens due to server cache.

In Smart Slider 3.5.1.13. we have modified our database tables to ensure MySQL8 compatibility. One of these changes were, that within the [prefix]_nextend2_section_storage table we have modified the system column's name to isSystem. The error message on your website tells, that some PHP file still wants to use system column name, which means that either that PHP file wasn't updated, or your server's cache serves an older version of it.

Solution

To make sure there weren't any update issues where some files weren't moved where they suppose to be, you could try a reinstallation. Go to your FTP and delete all our folders:

Joomla:

\administrator\components\com_smartslider3\
\components\com_smartslider3\
\libraries\smartslider3\
\modules\mod_smartslider3\
\plugins\system\smartslider3\

WordPress:

• Free: \wp-content\plugins\smart-slider-3\
• Pro \wp-content\plugins\nextend-smart-slider3-pro\

Your sliders will stay, so you don't have to worry about them!

Then install the latest version of Smart Slider. This would ensure, that the latest versions of files are on your server. 

If you would still see the same PHP error message after this, it confirms that you have a server cache caused issue. You should get in touch with your server host and ask them to resolve this issue for you. They should clear your server's cache, maybe turn it off, and then this issue won't happen anymore. And they should also make sure, that this issue won't happen in the future.