Module development and code questions

Just recently ran into an issue where the site is including a captcha_sid and captcha_token twice and they are different values. This is causing a reuse error. Google searching I found other reuse error cases but none that seems to apply to my instance.

<input type="hidden" name="captcha_sid" value="2286952" />

<input type="hidden" name="captcha_token" value="5638a7ed31fb98c597661ec8e71e4618" />

Hi,

I am using flexslider for create public or private video slider. Slider working fine but when I change slide the video not pause. I need previous slide video should be pause .

Thank you! 

I am doing tests to check, in the submit phase, if the node I am inserting is already present or not. The control can be on one or more fields.
I don't know if the solution I wrote is right or not. I tried with the title field and it works, it seems to work also with the entity reference (field_livello), it doesn't work for me with the data field and I didn't understand how to do it.

Here is the code in form_alter
   $form['#validate'][] = 'liveContra_validate';

I have been trying to develop a website and I need some help with it, it should take no longer than 30 minutes. my email is guptaru1@msu.edu, I would appreciate it if anyone could help me,  thank you!

I search to use a hook to get all HTML content to replace certain occurrences on code.

I want use `DOMDocument()` to modify some elements.

My actual hook but I can't get all page HTML...

I'm starting the process to migrate my custom modules to D9. Some things are easy, like replacing drupal_set_message(). This one is throwing me. My controller class is instantiating a database connection to a custom table and building a select query.

This works in 8.9.13