Sometimes a Gallery block doesn't display in the editor because of an error. React indicates the max amount of renders was reached, so the block is getting in an infinite loop. React links to this page for the error: https://reactjs.org/docs/error-decoder.html/?invariant=301 

This is probably because "setAttributes" is called in render.

For example on https://www-dev.greenpeace.org/test-neptune/wp-admin/post.php?post=19904&action=edit