E2049 Label declaration not allowed in interface part (Object Pascal)
From Appmethod Topics
This error occurs when you declare a label in the interface part of a unit.
unit Produce; interface label 99; implementation begin 99: end.
It is just illegal to declare a label in the interface section of a unit.
unit Solve; interface implementation label 99; begin 99: end.
You have to move it to the implementation section.