Fatal error when placing a block

Problem/Motivation

When placing the "canonical" link. I have a fatal error because, no pattern and variant are defined yet.

So the following code, https://git.drupalcode.org/project/ui_patterns_entity_links/-/blob/8.x-1...

    $pattern = $config['pattern'];
    $config['pattern_variant'] = $config['variants'][$pattern];

is failing because $pattern is empty.

I have commented those two lines and then I had been able to configure the block.

Once placed, when editing it is ok, but when placing not.