ID:13881 VHDL Interface Declaration error at <location>: subtype indication of formal <name> in Interface File Declaration must denote file subtype

CAUSE: In an Interface File Declaration at the specified location in a VHDL Design File (.vhd), you used a subtype indication for the specified formal that is not of a file type. However, the subtype indication must denote a subtype of a file type.

ACTION: Change the subtype indication so it denotes a subtype of a file type.