Diagnostic 7866: The statement following this DEC loop optimization directive must be an iterative do-stmt, a vector assignment, an OMP do-directive or a parallel-do-directive, or an OMP simd-directive or a do-simd-directive.
This diagnostic is issued when an Intel loop directive such as !DIR$ UNROLL or !DIR$ NOVECTOR is not directly followed by an iterative loop, an array assignment, or another directive that applies to loops. For example:
!DIR$ NOUNROLL print *, "Hello"
For more information, please read the Intel Fortran Language Reference section on Directive Enhanced Compilation > General Compiler Directives > Rules for General Directives that Affect DO Loops. If you need further assistance, please ask in our User Forums (Linux, OS X, Windows).