Drupal not generating image style thumbnails and associated directory structure

@desierto #5 working for me. Thanks for saving my day

Experiencing this issue but #5 is not working on windows dev machine using xampp, or LAMP environment on live server. I have to add the remote video (youtube) and save. Delete the video, add the video again and then the thumbnail is generated in both:

\sites\default\files\oembed_thumbnails\videos
\sites\default\files\styles\thumbnail\public\oembed_thumbnails\videos

This happens whether mappings exist or not. Is it a youtube response issue?

Hi ! same problem here, on Drupal 9.5.7
On production server as well as on Xampp, no images styles are being generated, for any style.
File system seems ok, other website on Xampp generate style with no problem.
I know the problem comes from this website configuration or some module breaking the processing of image styles but how to debug this ?
I tried to dpm() in ImageStyleDownloadController::deliver and ImageStyle::createDerivative with no result.
Has anybody any idea on how to deal with this ?

Yes. Use DDEV or Lando.

Thanks @desierto and @ahmadhalah
#5 and #7 save my day.
Ubuntu and Apache2

In our experience, on Siteground's NGINX hosting, a common issue for Drupal 8/9. For one particular project we inherited, also on SG, we noticed the following is enabled and set to true:

$config['image.settings']['suppress_itok_output'] = TRUE;
$config['image.settings']['allow_insecure_derivatives'] = TRUE;

Disabling both, seems to fix the issue.

Thanks for that headsup on mod rewrite. After spending hours chown, chgrp, and permissions this is what fixed it for me on Drupal 10.1.6

Have the same problem on Drupal 10.1.6 at the shared web-hosting with Apache 2.4.58 and PHP 8.1.25. To make custom images styles working and thumbnails visible I have commented option “-ExecCGI” in /public_html/sites/default/files/.htaccess and now it looks like this:

# Turn off all options we don't need.
Options -Indexes -Includes -MultiViews
# -ExecCGI

I am not sure is that the safest solution but it works for me.

@alfattal would you please share your virtual host configurations?