This is not working for me either. When I disable the ‘WPDM – Gutenberg Blocks’, it works again. Re-enabling the plugin makes it not work again.
What I’m doing for now as a workaround:
1) Deactivate ‘WPDM – Gutenberg Blocks’ plugin
2) Add/edit download package
3) Reactivate ‘WPDM – Gutenberg Blocks’ plugin
