Can not upload using core file upload element (no dropzonejs) because of false validation errors

Put in an MR for a new subclass of Drupal\media_bulk_upload\Form\MediaBulkUploadForm in the media_bulk_upload_dropzonejs submodule. Moved validateForm() as well as the contents of media_bulk_upload_dropzonejs_form_media_bulk_upload_form_alter() to the new subclass, and altered the bulk upload route definition.

Had the same issue after upgrading to 3.0.2.

Reviewed MR as at commit 06ea2f58ab7cb441440ff8303bfa2d6b551eae81 - looks good and resolves the issue when media_bulk_upload_dropzonejs is not enabled.

When media_bulk_upload_dropzonejs is enabled the MediaBulkUploadDropzoneJsForm form is used and validates as expected.

Attaching a patch file of godotislate's MR at 06ea2f58ab7cb441440ff8303bfa2d6b551eae81 for anybody that relies on a fixed point in time patch workflow. Thanks @godotislate!

Wow, that's a lot of code to review... Is all that code strictly necessary to fix the critical regression or is it more of an improvement?
I'm wondering if we can just put back the DropzoneJS check that was removed in 🐛 Validation missing when empty bulk media upload form submitted Fixed .

I guess I'm too busy or too lazy to dive in right now.
But why does the early empty check in HEAD even trigger?
I'll dive in later...

The only real new code is the route subscriber service in the media_bulk_upload_dropzonejs submodule. Otherwise, it's just moving code that was existing in the main module to the dropzonejs submodule, which really is where all things dropzonejs should go.

I faced the same issue in 3.0.2 and was able to resolve the same by enabling media_bulk_upload_dropzonejs and using https://unpkg.com/dropzone@5/dist/min/dropzone.min.js and https://unpkg.com/dropzone@5/dist/min/dropzone.min.css and placing them in libraries folder at libraries/dropzone/dist/min as new files dropzone.min.js and dropzone.min.css

Patch file
media_bulk_upload-can-not-upload-using-core-element-3355468-06ea2f58.patch

Tested , and Verified Its working
This Issue is fixed

Verified that the patch in #4 works and agree with the methodology: no dependent code should be in base module if the dependency isn't required.