Gallery ceased working after upgrade to 2.8.4

Summary

After an MODX upgrade to 2.8.4-pl (including update of gallery package to 2.0.0-pl) the implemented gallery ceased working. The main problem is that the link ( e.g. “https://***/index.php?id=64&galItem=137&galAlbum=38&galTag=” ) generated by the click on the thumbnail that used to show a larger version of the image with caption now displays the same page, i.e. galItem=137&galAlbum=38 are ignored. Another minor problem is that the thumbnail is way smaller now.
Another aspect of the problem is that the manager (in Extras->Gallery) does not allow to edit the contents of a gallery anymore.

The captions are available in table modx_gallery_items (field description)

Problems

There are two problems here. I do not know the details of the how/whys of the original implementation. It seems to be a simple and straightforward gallery implementation of 2014, MODX 2.2.
Second, I do not fully understand how gallery is supposed to work in MODX 2.8.4.

Code

This is html code produced by MODX and placed at the position of the gallery

<div class="gal-item gal-item-active">
<a href="index.php?id=23&amp;galItem=11&amp;galAlbum=6&amp;galTag=" title="Foto_ZV18.jpg" >
<img class="" src="/***/assets/components/gallery/connector.php?action=web/phpthumb&amp;ctx=web&amp;w=100&amp;h=100&amp;zc=1&amp;far=C&amp;q=90&amp;src=%2Fbienenkunde2%2Fassets%2Fgallery%2F6%2F11.jpg" alt="Foto_ZV18.jpg" /> </a> </div>

Interpretation

The thumbnail is created, “gallery/connector.php?action=web/phpthumb …” still works. The connection from index.php to the gallery item - indicated by “galItem=137&galAlbum=38” - is lost.

Questions

Has the internal structures of the mysql-tables modx_gallery_albums modx_gallery_items modx_gallery_album_items modx_gallery_album_contexts changed substantially that backwards compatibility is lost?
Has the connector from MODX to the gallery package changed?

Plan

I’d prefer to repair the site on the basis of the original mysql-tables.
If I’d understood how the current gallery function is supposed to work (including how the content is managed) I could also transfer the

Side note

There is another part of the page which uses prettyphoto. The link https://***/index.php?id=145#prettyPhoto[iframes]/0/ works fine: it displays an item (a frame of a separate site in this case) on top of the actual page. How can it be that prettyphoto still works but the more

Gallery manager issue

In the gallery manager, right clicking on a gallery and “edit Album”, there is an error message:
“Could not find action file at: controllers/default/home.php”
This file does not exist and did not in the old installation. Where does this come from, and how to repair it?

Have you tried clearing the browser cache?
It kind of looks like some old JS-files are used that should have been updated.

Yes, thanks! This resolves the Gallery manager issue.

The rest is still open.