Java 7 is now required to run AOTBT with the latest update. On debian/ubuntu/mint etc linux, Openjdk6 seems to be the most popular Java implementation. If you're using it, here's how to upgrade: First, uninstall Openjdk6. Open a terminal, and run this command $ sudo apt-get remove openjdk-6-jre (note - the $ character isn't typed in this and the following commands, only type what's to the right of it) This command may automatically install Openjdk7, but if it doesn't, run the following command $ sudo apt-get install openjdk-7-jre Now try running the Technic launcher with Openjdk7 (right click, open with OpenJDK Java 7 Runtime) In my experience, the launcher wouldn't run with only Openjdk7 installed. If this happens to you, you could try installing Oracle's proprietary Java implementation, with the following commands (and remember, the $ characters aren't typed, only what's to the right) $ sudo apt-add-repository ppa:webupd8team/java $ sudo apt-get update $ sudo apt-get install oracle-java7-installer Wait for the installation to complete, and then try running the launcher with Oracle Java 7 Runtime. I hope this helps, and please comment if you need further help.