500 internal server error on custom_block

Dear community,

We’ve set up a website for a customer with purchased Drupal 8 theme ‘omni-consultancy’. On the development server things went fine, but on production (a different server, shared hosting, php 5.6.33, fastCGI enabled) we have issues with custom_blocks.

When admin-logged-in-to-drupal and trying a read or edit for the url of any custom block (for example http://site.com/block/60/) the following occurs:

500 internal server error

The error_log reads the following

We’ve contacted the webhost (Hostnet.nl) because we suspected a server configuration to cause the problem (something to do with fastCGI perhaps?) but they couldn’t help us and said it was a Drupal related issue.

Additional info: The statuspage reads the following:

Errors found:

  • Non-matching entity and / or field definitions

The following changes were found in the entity type and the field definitions.
Custom block

  • The Create date time field must be updated.
  • The User Version field must be updated.

Any idea’s on how to fix this? The custom block module is used in many places throughout the theme.

Drupal version: 

Source: https://www.drupal.org/taxonomy/term/22/feed