I have 64bit Ubuntu 12.10 installed with an Intel® Core™ i5-3570K CPU. I use Chromium. I have installed OpenJDK 7 but whenever I right-click the .jar file and click "open with openjdk java 7 runtime" nothing happens at all. I have tried this with OpenJDK 6 and nothing happens.
Could it be a 64bit conflict? I have also tried a different minecraft.jar and nothing changed. The .jar is set to executable.
Please help.