Please explain in more detail: So it is hard to tell what might be the problem.
Especially with Viveza.
What is your Viveza version? What is your Aperture version? Are you running the latest Aperture 3.4.5? And what is your MacOS X version?
I have uninstalled and reinstalled several different times with no luck...
What did you reinstall? Aperture? Viveza? MacOS X?
There have been known problems with Viveza, that have been fixed with the Update to 3.2.4.
Another problem may be duplicate Arial fonts, see NIK's page:Crashes on Mac OS
https://support.google.com/nikcollection/answer/3002572?hl=en&ref_topic=3001470
Regards
Léonie