It's hard to tell from the mail formatted commands but thoughts off the top of my head:
1. /S /v"/qn looks like it might need an additional space: /v "/qn
2. Have you tried to register the output of the task and then subsequently inspect that? If so... what's the output?
3. Have you tried using the argv parameter to see if that helps C:\VMware-tools-12.1.5-20735119-x86_64.exe parse its arguments more cleanly?
4. If you drop that heavily quoted command line into a powershell or batch/command instead and copy then call it... what happens? (Purely from a debug/problem reduction perspective?