Module development and code questions

I'm developing a complex AJAX form and it works under the core themes, like Bartik. But switching to the customer's theme brings up this error when submitting the form.

Ah, you say that clearly this theme function is goofed up. To ensure it wasn't something in my form code, I copied over the ajax_addmore from the examples project which is much simpler to walk through and debug.  I wish it were as simple as that, but in watching it go through the ajax_addmore form it doesn't bail as it goes through each of the AJAX steps. When it bails on the submit step, it fails at line 1008

I have a few hundred users in a plain vanilla Drupal 9 instance on my local machine. They were created using the standard Drupal migration tool from our production Drupal 6 website. I need to get these users copied into our new production Drupal 9 site which is currently under construction. I have tried a few of the migration tools available but - at least any way I have tried so far - they have totally hosed the new web site.

Hi guys!

I was wondering if anyone could help me with module creation - I need to create a module in drupal 7 from scratch. It's a ticket booking module. Is there anyone willing to provide guidance or even paid tutoring, as I'm completely new to this.

Thank you in advance! :)

Hi team

I have one issue,
I've created some items for a content type on my develop site, I've created something like 30 new items and i would like to export them and import on my production site

How can i export them and import on my production site?

I've tried using Configuration synchronization but i dont know how to export all my items.

Could you please help me?

Regards
Mario

Hi Drupal-Gang,

Edit------

Maybe it would be easier to describe more my problem. I´ve got a vocabulary "tags" and nodes and media objects. Both are referencing to this vocabulary. My content type "Post" has the field "field_mt_post_tags" and my media object "Image" has the field "field_tags".

I want to create a block, which is shown on the node pages. The block has to include the media objects which is also referenced to all tags of the node.

For example:

Media Object A is referenced to 1,2,4,5,6,7

Node Object A is referenced to 1,2,4,5

Trying to use the views grouped filter instead of exposed but trying to override the feature when using checkboxes and "allow multiple" it replaces them with a select after going above 4 filter options. It's in the filter plugin for Views in the spot below. Is there a way to do it via hook or is it too hacky of an ask?