Cannot start up COMSOL 44

Hi,

I have installed both COMSOL 43a and COMSOL 44. I used to be able to use both, but suddenly - after rebooting my computer (I work on Linux) - COMSOL 43a starts up fine, but COMSOL 44 has a problem.
When I go to the log file, I get a long list of error messages.
First a long list of !ENTRY / !MESSAGE errors about org.eclipse.osgi and then a JAVA error "Could not find the COMSOL Application 'com.comsol.guiclient.application'".

How can I solve this?

Example:

!ENTRY org.eclipse.osgi 2 0 2014-03-28 10:36:20.013
!MESSAGE One or more bundles are not resolved because the following root constraints are not resolved:
!SUBENTRY 1 org.eclipse.osgi 2 0 2014-03-28 10:36:20.013
!MESSAGE Bundle update@plugins/org.eclipse.swt.gtk.linux.x86_64_3.8.1.v3834e.jar was not resolved.
!SUBENTRY 2 org.eclipse.swt.gtk.linux.x86_64 2 0 2014-03-28 10:36:20.013
....
....
!ENTRY org.eclipse.osgi 4 0 2014-03-28 10:36:20.017
!MESSAGE Application error
!STACK 1
Exception:
java.lang.RuntimeException: Could not find the COMSOL Application 'com.comsol.guiclient.application'
(rethrown as com.comsol.util.exceptions.FlException)
Messages:
Could not find the COMSOL Application 'com.comsol.guiclient.application'
....