Hi I had the same problème .. It’s look like the have or they gonna patch gutenberg ..
here on the git hub
I simply change the line : 237 of : gutenberg/lib/block.php
if ( ! $block_type || ! $block_type->render_callback ) {
return $block_content;
}
by:
if ( ! $block_type || ! $block_type->render_callback || empty( $block_type->supports ) ) {
return $block_content;
}
It work for me .. and just wait for the patch ..