Not showing thumbnail in WordPress editor

@slabbi – Thanks for creating your own topic!!

Have you worked through the steps outlined in this article: https://codex.www.ads-software.com/Managing_Plugins#Troubleshooting

I definitely suspect a plugin conflict here and those steps should help pin point the issue.

Thanks, again!

– Cais.

I have checked most of the steps.

I wonder why there is an extra break. Even when I disable all other plugins it is still there.

@slabbi – IF there are unexpected characters being printed to the screen with *all* plugins deactivated then this could be theme related … at least as far as these characters are concerned.

– Cais.

Nope. I use Catch Everest on my site and checked it with following themes: Twenty Fifteen, Twenty Thirteen and Expound.

I have installed WP in a sub-folder called “wordpress\”. Maybe this might cause the trouble?

@slabbi – What parts of the troubleshooting steps did you not check? Those may be key to the issue at hand.

– Cais.

I tried everything.

Joking aside, I can send you a login so you can check yourself (to which email shall I send the credentials)?

@slabbi – We strongly recommend you actually do follow those steps thoroughly but as is, if you want us to have a look under the page then you can send us a Bug Report here: https://nextgen-gallery.com/report-bug/

Thanks!

– Cais.

There is another problem which I haven’t recognized before because you have to insert a new gallery in order to see the problem:

Pressing the green editor button to insert an existing gallery opens blank window with no elements in it (usually you can select the style and gallery there).

The site runs for a long time now and with each update NextGEN becomes more buggy. Guys, I have already bug fixed your code in the past and when I check the code again I am pretty sure I will find the bug. It does not really help to point a user to a general trouble shooter. I have already disabled all plugins, reinstalled NextGEN, checked for CSS and Javascript problems with Firebug etc. Nothing helped.

To be honest when there would be another Gallery that fulfills my requirements I would switch to that immediately and trash the buggy piece of software called NextGEN.

Ok, first bug seems to be fixed:

I removed
while (ob_get_level() > 0) {
ob_end_clean();
}
in /wp-content/plugins/nextgen-gallery/products/photocrati_nextgen/modules/nextgen_data/package.module.nextgen_data.php line 3343
and the preview image is displayed again in the editor.

Unfortunately when clicking on the picture the windows opens (you can also see the close X) but without any elements like before.

When moving the mouse over the window that should contain the elements to select the gallery etc. Firebug shows following error:

Error: TypeError: self.parent is undefined
Source File: https://xxxxxxxx.de/wordpress/wp-content/plugins/nextgen-gallery/products/photocrati_nextgen/modules/frame_communication/static/frame_event_publisher.min.js line 1 > eval
Line: 1

After becoming more and more annoyed because of the thousands of bugs that NextGEN 2.x introduced I finally found a solution in the 1.9.x branch of NextGEN: Nextcellent Gallery.

https://www.ads-software.com/plugins/nextcellent-gallery-nextgen-legacy/

Works fine, Galleries etc. are shown again, site is much more faster again. Great.

Each update of NextGEN brought new bugs and broke sometimes functionality. Hopefully this odyssey has ended now.

@slabbi – Best of luck going forward.

– Cais.