Hi there!
I need more information than "it's simply not working". There are some things that you must do to make them work.
But first, we need to see if this is a compatibility problem with the Dot move System. So, set it to off on your plugin manager, and make my Diagonal Character works first. After you manage to do that, then you turn the Dot Move System On again and test both plugins together to see if they will work.
Now, to help you make the Diagonal Sprites work, show me what you did on your character filename. Did you follow the help file instructions? Changed the filename properly? Show to me what you did so we can try figure out how to make it work :)
Also, you should only have one row of characters on the file. Just like the screenshots on the help file.