The Error number is -199. (For internal reference only!)
appears upon startup and exits from the program proper, such that POV-Ray becomes useless (not pleasant when you need that last minute image 30 seconds before lecturing).
The only mention online (if you search by the message text) can be found at
The error itself is not diagnosed, only noting that a corrupted file is not being accessed upon startup and that running a Disk Utility verification/fixing and reinstalling POV-Ray solves the problem. If this has happened to you, you may have noted that verification/fixing and re-installation does not do the trick.
The origin of the problem on my machine could be traced to a crashed POV-Ray rendering run of a number of images and the retention of the file POV-Ray Mac 3.6.plist in my /[USER]/Library/Preferences/ directory, which typically only contains the file POV-Ray Preferences 3.5 (why an installation of POV-Ray 3.6 would still leave a 3.5 Preference file is beyond the scope of this post).
Deleting the POV-Ray Mac 3.6.plist file fixes the problem.