My brother is having trouble with Pentagon in 8.5. It used to be flaky, but now it just doesn't load. I've come up with no solutions, either on my own or on the forum. I was having next to no trouble with it in X1 essential, but my pc died on me. So, I'm wondering if anyone is having any luck with Pentagon in X2 and either Windows 7 or Windows 8. Any experiences would be appreciated, as I'm trying to decide whether to encourage him to upgrade, and whether to upgrade myself.

Pentagon runs in X2a 64bit Win 7. It requires SONAR run as administrator.

D00d I've had so many problems with this synth. I had it once, then projects wouldn't load it anymore even though it was present. I bought it again and reinstalled and now projects with it hang when it's activated in the synth rack. Such a shame because I love the sound of it, but yeah it's a bear. 

Seems to work for me with no issues.  I run Sonar as administrator.

Bob Bone

Works OK for me apart from the well know "Valley" simulator issue. Any patches that use this effect will stop the audio engine and/or produce a very loud burst of noise.
 
Something is screwy though for so many people to be having problems with it.

I had immense problems getting Pentagon to run in X1/X2 but running Sonar as Administrator (as suggested a couple of times) works perfectly.

A good solution is to right click on your Sonar shortcut, select Properties - Compatibility and check Run As Administrator under Privilege Level. This way you don't have to think about it each time you launch Sonar. 

D00d I've had so many problems with this synth. I had it once, then projects wouldn't load it anymore even though it was present.

Why X1b and not X1d? 
You need to get off Windows XP. 

Thanks for the responses guys. I had already set 8.5 to run as administrator for my brother, but it made no difference at all. For me, X1 was running fine (as well as Pentagon) on XP. My new system will be Windows 7, and I'm pondering the X2 upgrade. I'd hate to lose Pentagon, as it's my go-to analogue.

It might be time to start looking for an alternative. The Pentagon dll shows a last modified date of 2005. Although it works for me, given how many have reported problems with it (apparently unrelated to the known permissions requirement and valleys simulator issue), I would not want to depend on it.