Hello,
The Print button on VAT Returns appears inactive because unhiding the action is not enough—the user must also have permission to run the underlying VAT Return report and read VAT tables (VAT Return, VAT Return Line, VAT Entry), otherwise clicking Print does nothing; once those report/read permissions are granted, both open and closed VAT returns can be printed, and as a practical alternative many teams export VAT returns (Excel/XML) or have a power user print and share the PDF instead of giving full VAT permissions.
Regards,
Oussama Sabbouh