These are common errors that users have had between Minecraft and the Twitch App. If you are having issues with Minecraft please refer to Mojang for assistance. If you are having issues with a specific mod or modpack please refer to the mod or modpack's author for assistance. This download runtime is basically a file that the Minecraft launcher is trying to find. The file that Java is trying to find is called Java Runtime Environment. It couldn't find it on your computer, so it has to download it. What you can do to get rid of it is just download Java. Can we get 500 like for this video if you cant get to the appdata folder so open start menu and type%appdata% then you will get roaming,click on the roaming. The Minecraft Updater gets most of the way through 'Updating Java runtime.' And hits me with 'Unable to update the Minecraft Runtime Environment.' I have attached the full launcher log text file.
Mac client instructions
You need to have a version of Java installed on your system. If you do not have a suitable version of Java installed, the following error will be presented - 'Unable to load Java Runtime Environment'
To install the Java Runtime Environment, please visit java.com
If you receive an error when installing Java, see this page
To install the game client:
Double click .dmg to make its content available
Drag the application from the .dmg window into /Applications to install (may require administrator password)