have both openjdk-6-jre and openjdk-7-jre installed. Minecraft.jar requires 6. At some point, the file association for 6 disappeared (used to have options for both), and I can only associate the file with (incompatible) java 7, or archive manager (useless.) was working for several months. Total mystery how to create associations in unity, so stumped.
to reproduce, have a minecraft.jar on the desktop. click on it, something useless happens. right click to change file association, no options available for java6, in spite of it being installed.
ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: unity 5.4.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-16.25-generic 3.2.6
Uname: Linux 3.2.0-16-generic x86_64
ApportVersion: 1.91-0ubuntu1
Architecture: amd64
CompizPlugins: [core,bailer,detection,composite,opengl,compiztoolbox,decor,place,vpswitch,resize,mousepoll,wall,snap,grid,gnomecompat,move,imgpng,regex,session,animation,workarounds,fade,expo,scale,ezoom,unityshell]
Date: Sat Feb 18 09:51:12 2012
InstallationMedia: Ubuntu-Server 11.10 "Oneiric Ocelot" - Release amd64 (20111011)
ProcEnviron:
PATH=(custom, user)
LANG=en_US.UTF-8
SHELL=/bin/bash
SourcePackage: unity
UpgradeStatus: Upgraded to precise on 2012-01-15 (34 days ago)
the issue there was rather java not installing the proper entries and it seems to work in newer versions