Removing a shipyard core anchor while a design is loaded, will delete that design entity from the database. The meta item in your shipyard computer remains though and when you try to load it, it will give you an error saying:

Cannot load design Entity for design not valid in database!

The design should unload, not get removed the database. This corrupts any loaded design. Sometimes a shipyard gets stuck (see T762/T752) and removing the shipyard core anchor usually gets rid of that. Doing that though will inevitably corrupt the design you had loaded at the time.

How to reproduce:

1. create design in a shipyard
2. delete the shipyard core anchor (in station build mode)
3. place it back and link it to your shipyard computer
4. try to load the previously loaded design, you can't