ID:13811 VHDL error at <location>: NOT unary operator cannot be applied to enumeration value "<text>" for enumeration type <type> because value contains non-bit elements

CAUSE: In a VHDL Design File (.vhd) at the specified location, you applied the NOT unary operator to the specified enumeration value for the specified enumeration type. However, the value for the enumeration type contains elements that do not have a bit subtype. You cannot apply a NOT unary operator to an enumeration value that contains non-bit elements.

ACTION: Make sure you apply the NOT unary operator only to enumeration values that contain only elements that have a bit subtype.