NextGen Version 3.3.17 and WPBakery Visual Composer Version 4.12.1 Cant work

WP 5.5.1
NextGen = 3.3.17

Site’s Front-end works great.

But when I tried to edit post or page in WP backend I’ve got “502 Bad Gateway”
for this link – mysite.com/wp-admin/post.php?post=13187&action=edit

Wp-admin access = 755
post.php = 755

When I disabled NextGEN Gallery – I can edit post or page.

Error log don’t show my explanation of a problem ?
define(‘WP_DEBUG’, true) in confing.php doesnt show me warning about it.
Cache for browser and site was cleared – it didnt help me for Backend post edit.

After that….

I’ve deactivated ALL plugins (and template and cache and more).

The source of a problem that 2 plugins can’t work together
NextGen Version 3.3.17
and
WPBakery Visual Composer Version 4.12.1

WPBakery Visual Composer Version can edit post and page without active NextGen.
When NextGen was activated and WPBakery Visual Composer Version is active – post \page is not edited.

I recorded video of my testing and sent to the support (at) tagdiv.

it’s ok. it was just info
Please take into account: 
WordPress Gallery Plugin – NextGEN Gallery 800,000+ Active Installations
WP Bakery – 4,300,000+ 

information was sent to NextGen support also. 

ok.ok, I’ll let you know, when find solution
And please note, WPBakery Visual Composer goes with your Template.

• This reply was modified 5 years by kibiribi.
• This reply was modified 5 years by kibiribi.

After manual Plugin update
from WPBakery Visual Composer Version 4.12.1  ===> WPBakery Page Builder Version 6.2.0 problem was disappeared.
Page edit works well.

The problem was that Visual Composer was very old.
The case is closed.
Thanks for the support!