Whitescreen an JS exception when editing site

Hi,

lately when I want to edit a certain site using the Atomic Blocks theme and plugin I get a whitescreen. The console gives me the following JS exception:

blocks.min.js?ver=6.0.6:2 Block validation: Block validation failed for atomic-blocks/ab-cta ({name: “atomic-blocks/ab-cta”, title: “AB Call To Action”, description: “Add a call to action section with a title, text, and a button.”, icon: {…}, category: “atomic-blocks”, …}

It further on shows me what the expected and the actual output was. The only difference is, that the button link on the call to action block contains a rel=”noopener noreferrer” on the actual output which does not seem to be expected by the Plugin.

Is there a workaround or is it a little bug that can be fixed? The issue started after the update to WordPress 5.1.

Thanks for your help!