Parallels Desktop 8 update 8.0.18608.898384 won't install, conflicting apps error

Parallels Desktop 8 advised an update was available. No virtual machines were open/running at this time. Clicked install button, but partway through download "Conflicting Applications" error appeared with "Parallels Virtual Machine" as only item required to quit. No such application was running; no virtual machines were open. Quit Parallels and downloaded update directly from website. Double-clicked installer app, and same message appeared. Please advise. Thank you.

Karen