davmail crashing on startup

so, I finally updated davmail (4.1.0-2042 ) after it asking me to for literally years. But when it started up startup, it immediately crashed. At the same time, I got an error relating to the jre. A quick google got me to some information about how sometimes the open jdk is better than the sun java. So I checked which one I was running with:

sudo update-alternatives --config java

 which gives me:

There are 3 choices for the alternative java (providing /usr/bin/java).

  Selection    Path                                            Priority   Status

------------------------------------------------------------

  0            /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java   1061      auto mode

  *1            /usr/lib/jvm/java-6-sun/jre/bin/java             63        manual mode

 2            /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java   1051      manual mode

Press enter to keep the current choice[*], or type selection number:

I switched to  [2], and now it runs!