Resolved
Resolved in: 3.0.2
Toolset officially works with WordPress 3.4–5.3.2, however, if you activate Toolset Views or Blocks on a site running WordPress 4.9.12 or 4.9.13 you’ll get the following fatal error:
PHP Fatal error: Uncaught Error: Call to undefined function OTGS\Toolset\Views\Services\register_block_type() in .../wp-content/plugins/wp-views-old/backend/Services/Bootstrap.php:44
There is currently no other solution but to update WordPress to a newer version.
Our developers are aware of this issue and will look into it.