Strange that it’s not working now when it was before…
Aside from the re-install, you could try trashing preferences, and see if that makes any difference.
On my system they are found in Macintosh HD -> Users -> [Myusername] -> Library -> Preferences -> Media 100 Suite Preferences.
If the library folder is hidden, you can toggle in the finder between showing or hiding hidden files and folders with the keyboard shortcut: APPLE + SHIFT + FULLSTOP.
And of course, by fullstop I mean a dot or period or whatever you wish to call it – ” . ”
There are also different ways to bring up the ColorFX window.
Is it just one particular way that’s failing, or all methods?
Is it possible it is appearing, yet in a different screen space?
Use the Mission Control app in the applications folder to view all spaces and all windows.
More info on opening Mission Control: https://support.apple.com/en-gb/HT204100
I figured it out, After all these years using media 100, somehow when hit “Arrange all” in the window pull down menu, It fixed it! Never encountered this before, but fixed it, Thanks for answering back.