Had a black screen on start up. GUI elements were visible but nothing of the game world. Double checked the notes on the download page (Fast Ranger OFF, Shaders OFF) -- these were set correctly, so I decided to go through the video settings one by one. First on I tried was disabling antialiasing. This turned the screen full white instead of full black, but after a restart the game was working perfectly with both installed.

I suspect this is probably an unavoidable issue, but should be added to the curseforge page under "Optifine caveats" as it's likely to be a common problem.