Timeout happened, so it seems I might have steered you in the wrong direction, I think it’s saying it couldn’t match the contents of mx.png to somewhere on the screen within the timeout.
I found I got best results with SikuliLibrary by making the images as small as possible to get a unique match, Using the reply button from this forums form as an example:
this would gave me a better match result
this would give a worse match result
The difference is subtle but it made a big difference to the reliability of my test cases
The other thing I encountered was related to screen scaling (retina display’s on MacOS), I found the screen shots were too high resolution or too high dpi, can’t remember which so I had to down scale my images, so you might need to do that too?