Solid Filled - Inverted Channels - Separations That Look Completely Wrong!
REASON WHY THIS HAPPENS AND HOW TO EASILY FIX:
This occurs due to an Invert function of Photoshop's Color Range Tool not resetting properly. If one of our Actions makes use of Color Range for only a single purpose with Color Range set to Invert, this can impact the entire separation resulting in solid or inverted channels. Although our scripts do contain a command to reset Color Range to its default, some versions of Photoshop do not respond to it.
How To Fix:
Simply restart Photoshop and the issue will be resolved.
Restarting Photoshop will reset the Invert function to its default value.
Another way to resolve this is to make a new channel using Color Range and make sure to uncheck Invert prior to clicking OK. Any type of channel can be made with any type of selection. The primary goal is to uncheck that Invert check box.