1) I understand this was working before.... but, normal installation is AC first, with wibukey NOT plugged in, then install wibu.
2) If this AC was working fine and you made no changes to it prior to problems, then, you most likely need to start some computer maintenance. Such running virus, worm and spy-ware detection and removal software.
3) After 3 years, you may be running out of free disk space or have too many programs that load themselves into memory. I don't know the MAc version of getting rid of memory resident programs, but doing that on your Mac might help.
4) Remember to actually run an "uninstall" of AC, don't just reload it with the repair option, fully remove it.
5) Post your equipment information, such as: RAM memory, AC version and Hotfix #.
6) What did the screen shot tell you about the problem? Quote the error message on this forum, that might help.