Why is the 're-store' button not clickable?

Why is the 're-store' button not clickable?

Even if you have the correct Security Group and Permission Set that allow you to delete records in a specific module and register, the ‘Restore’ button may still be greyed out.

This usually happens when the record is part of a parent–child relationship. The child item cannot be restored until its parent item has been restored first.

Example

A bowtie risk has been created with a cause and preventive controls added.

If the Cause (Parent Item) is deleted, the ‘Restore’ button for the Preventive Control (Child Item) will be greyed out.

Once the Cause (Parent Item) is restored, the linked Preventive Control (Child Item) will be automatically restored as well.

You can learn more by reading the article on Restoring Deleted Records.