Hello again, Ladies and/or Gentlemen, I have found another method to reproduce this problem that perhaps is clearer: Open the attached file. Using the mouse, select Edit | Select All . Using the mouse, select VHDL | Comment | (Un)Comment Out Region. Line 14 will now be rejected by any VHDL compiler. The file is saved to disk as it appears on the screen. I checked with another editor. Cheers John