hi guys, I recently upgraded to windows 10 and suddently I had this problem too, and I FIXED RUNNING SONAR AS ADMINISTRATOR.
here is how I solved this:
right click on sonar icon
click on properties
click on advanced
check the box "run as administrator"
ok, aply, etc
and... PROBLEM SOLVED. it solved as well another issues I had with another 32b plugin: Speakerphone from Audioease.
just one thing: you MUST open sonar by doble clicking the icon from the desktop (or wherever you have its shorcut) and once opened, you must open your project using sonar's menu. DON'T OPEN SONAR BY DOUBLE CLICKING ON YOUR PROJECT'S ICON, since it will open sonar not as administrator and it simply won't work. do this at least the times you are going to use Philarmonik.
hope it helps.
(if it doesn't work the first time), open plugin manager, under VST options check the 2 Re-scan boxes and do a scan of your VSTs. after this, it will work, an you may get back to plugin manager and uncheck the 2 Re-scan boxes again.
my equipment:
intel cuad processor Q95590
windows 10 pro
sonar platinum 64b