FORCDK-MENU-005
Thrown by forty-cdk/menu.
[forty-cdk/menu] FORCDK-MENU-005: The [forMenuSub] holding this [forMenuSubTrigger] has no parent menu.
Cause
A submenu opens from an item of the menu above it, so it needs an enclosing menu.
Fix
Nest the [forMenuSub] inside a [forDropdownMenu], [forContextMenu], or another [forMenuSub].