Unclassifiable Statement at SUBROUTINE declaration inside a PROGRAM

Question

So I\'ve written a basic Vigenere Cypher in Fortran 90, however when I try to compile it, I am hammered with Unclassifiable Statement Errors due to my internal SUBROUTINES.

Answer 1

You are missing CONTAINS before your subroutine.

In the future learn modules, but now use CONTAINS to make those subroutines properly internal to the main program.

So it should look like

PROGRAM Assign_8
  ...

  CALL Validation_Sub

CONTAINS

  SUBROUTINE Validation_Sub(Path, Validation)
  END SUBROUTINE

  ...

END PROGRAM Assign_8