Can't able to upload the images

Agreed.

I have a paid-for Cloudinary account and we have been using it with our site for 5 years.

The error we have is:

The specified file '/tmp/phpRyCHmT' could not be copied because the destination directory 'cloudinary://inline-images' is not properly configured.

However this ONLY happens for inline images created using ckeditor 5. The standard media manager works just fine.

This error is generated by Drupal, probably because it tries to access the Cloudinary directory (in the prepareDirectory() method of FileSystem) directly which obviously it can't do.

A further look shows me that very early on it uses is_dir() on the directory alone which returns false but later calls $this->mkdir() which works (because that goes through the streamwrapper). But then it comes back and thinks the full filename must be a directory, which then fails, so the upload fails.