When upgrading from a previous version, make sure you update the table structure (
bin/console doctrine:schema:update --force
or bin/console doctrine:migrations:diff && bin/console doctrine:migrations:migrate).
A new field to store the original filename was added to the Media table, so you will have to update the table structure when upgrading from a version prior to 2.3.18.
You can use bin/console kuma:media:migrate-name to initialize the original filename field for already
uploaded media (it will just copy the contents of name field into the original_filename field, so you could also just
update this using a simple SQL query if you want).
The Folder entity has been refactored to be a nested tree, which should speed up the media section (this will especially be noticeable if you have lots of media folders).
To migrate your current media tree to the new format, you have to execute bin/console kuma:media:rebuild-folder-tree
to initialize the folder tree. If you decide to undelete folders you should run this command as well.
If you want to create PDF preview images for PDF files that have already been uploaded (provided that you have the
necessary PDF support enabled), you can run the bin/console kuma:media:create-pdf-previews command.