This blog post describes how you can fix the Twitch Minecraft Launcher only showing a white or black screen.
Twitch App Minecraft Not Working At All Mac Os
One such game is Minecraft, and several users are facing this issue where they are unable to connect to Minecraft servers using Hamachi. Hamachi is a powerful app, but is built for an average user.
Minecraft launcher showing white or black screen
This blog post aims to fix the issue where the Twitch Minecraft launcher only shows a black or white screen. This prevents Twitch from properly launching Minecraft.
Fixing the issue of white/black Minecraft launcher

To fix this issue we can force Twitch to load Minecraft using the jar launcher. We can set this option in the Twitch settings.
To enter the Twitch setting we need to select the Twitch menu on the top left and then press File -> Settings.
Minecraft Twitch Mods Not Working
This loads the below settings interface.
Along the left hand side you will want to select the Minecraft option. Here we change the Launch method to “Jar Launcher”.
Twitch Mods Not Working
Once this has been selected you can press “Done” and launch Minecraft.
Twitch Mobile App Not Working
When the Jar launcher pops up it may show a popup with the title “Outdated launcher”.
Twitch App Minecraft Not Working At All Mac Games
This is because it detects that you were using the newer Minecraft Launcher. For this fix to work you will need to press “I’m sure. Reset my settings.”.
Twitch Not Working On Pc
Once this is done you may need to log into Minecraft. Once this is done you will be able to play Minecraft as normal.