Okay seems that after a migration your media point not to the right directories. So don’t be so stupid as me and check all so at settings->media if the directory is correct. Sometimes the solution is so simple and you think too hard for a difficult solution.
I moved the entire uploads directory to the default location. Not sure exactly why a standard WP install can easily move the uploads folder but a multisite install causes this problem, but there it is. I removed the line in the wp-config file and also moved the directory on the server.
If you are using custom theme, please add this in the functions.php: add_theme_support( ‘post-thumbnails’ );
I found it after trying with several hooks. Use ‘init’ and check if $_FILES is empty, if not, do what you want to do. init hook
WordPress discards PNG file when uploading plugin file
This is the only article I could find that seems to address such a generic issue. They specifically talk about the generic “HTTP Error” message that you report. Sorry! I know it is very frustrating. Hope they have the answer you need!
upload multiple images using wp_handle_upload
This will not work the way you are thinking. WordPress will try to upload attachments (images, pdfs, etc) to your server using the UPLOADS constant, this path is a file path, local to the server. If you wish to use a CDN you can get a CDN service to do this (manage files and upload … Read more
WordPress5.2.3: Better File Download Plugin validation issue
All files in public_html, Cannot launch WordPress site via wp-admin