Yea I got this bug too in one of my maps and have no idea what's causing it. I had to create a new diff as a workaround. Not sure how to replicate it either, but here is a link to the map file. Does anyone else have issues seeing the notes?
Which diff did you have problems with? I can see the notes in all non-empty diffs just fine in both F5 and actual play mode. I could also see the circles I placed in [ttt] and [aim].
yeah that skin has transparent combo numbers and slider ticks and the map's skin has everything except combo numbers transparent, so you can only see slider borders, slider balls, and slider follow circles with that skin on that map