Anyone having Vocalsync issues?
Suddenly Vocalsync is no longer working.
It either ERASES the selected track (undo brings it back) or gives me an error saying something like "Program error.  The guide track cannot be .... it may be empty".
 
Any thoughts?
 
My SONAR is really going to crap lately.  CONSTANT crashing and now this.  Yay!

Have you tried rebooting?

Oh yeah! 
I've tried rebooting, I've reset my interface.
Vocalsync no longer works. Now, as of tonight, Melodyne no longer works.
I wish there was some way of reinstalling just Vocalsync.
Apparently there is a "Region Effects" issue.

The program itself seems to be degrading.
 
As soon as I finish this album (I hope SONAR allows me to finish it) I will reinstall Windows and if that does not fix SONAR's CONSTANT crashing I will be forced to find a new DAW.  Which would be sad as I have used Cakewalk since 1991.

I HIGHLY recommend upgrading to Windows 10. You can do an in-place install so you don't have to wipe your hard drive, and you have 30 days to roll back to what you were using before if you change your mind.
 
You are experiencing anomalous behavior to say the least. Since updating to Windows 10 SONAR has super-stable for me. I go through weeks of heavy use without crashes; when freezes occur, I can usually trace them back to a specific plug-in or driver. BTW also check to make sure you have the latest Focusrite drivers.
 
My main concern is I highly doubt you are experiencing a problem inherent in SONAR. It could be some system interaction with SONAR that's causing the problem (installing Windows 10 may solve that) but because you say SONAR is "degrading" that implies some kind of system issue that will rear its ugly head even if you switch DAWs. SONAR doesn't really "degrade" by itself. I also recommend doing a RAM test that you can run from a command prompt in safe mode. I've had "degradation" problems on both Windows and Mac that turned out to be a RAM stick going bad. 

Not sure what a RAM test is but I'll look into it today.  I will also check out the drivers for FR and make sure they are updated.
I will try anything to fix this.
There is NO pattern whatsoever to the crashing.  One day it will work fine (only crash twice) and the next day it just becomes unusable.
 
Last night I uninstalled/reinstalled SONAR with no results.
 
And the degrading continues, as now Melodyne doesn't work.  When the Fault Reporter comes up I see the word Melodyne in there, so obviously something is going on there.

I was going to recommend the memory diagnostics in Windows 10 but then I remembered you don't have Windows 10...not sure if there's something similar in 8.1, but try MemTest. I've used it before on Windows and Mac (where it discovered a problem that had eluded all other attempts at a solution), but bear in mind you need to run at least 8 passes to have some degree of confidence your RAM is okay.

Yeah, you shouldn't be having that happen to you. I was going to suggest uninstall/reinstall of Sonar  but since you've already done that, try doing the same with Melodyne. There's also a version 4 update you might consider.
 
Craig's advice on running a memory diagnostic is right on. In Windows 8.1 it's easy - at the start screen (or search) type "wmd". This is the Windows Memory Diagnostic. Run it and follow the prompts.
 
Next, I'd check the Windows Event Log to see if any hardware issues are being logged like disk errors or other hardware failures.  After that you might want to go into Windows Update, check the history and see if any updates were applied around the time you started experiencing issues. It wouldn't be the first time a patch of the OS hosed things up. If so, and I wouldn't go here lightly, there's usually a restore point created when an update is done that you can roll back too, BUT if you decide to go this route, backup any projects you've changed; you'll lose any changes since the restore point was created.
 
Honestly, I don't think you'll have to get that weird. Problems like this are almost always resolved with uninstall/reinstalls of something, be it drivers or specific software components.
 
Good luck!

2 things to suggest monstaar
 
1 - did you follow the full instructions contained here:
 
https://www.cakewalk.com/Support/Knowledge-Base/2007013392/SONAR-2015-Clean-Install-Instructions
 
2 - locate and delete your aud.ini file, then restart Sonar (don't worry, Sonar will build a brand new one upon reboot)

Good Day,
 
I cant really help with your issue, but will say I just reluctantly tried using Vocalsync again yesterday, and it still had problem I had months ago, and why I don't use anymore, which is that as soon as I have tracks selected and try and move/align them it generates a high level noise signal that requires shutting down audio engine and/or global FX to mute, and then closing and restarting Sonar to stop noise generation.
Conversely, I've gone pretty well the whole month without Sonar crashing, (until using Vocalsync), from previous month which it was crashing at least 2 or 3 times a day. I had changed some Windows setting to include, always running as administrator; giving priority to back ground applications; and removing indexing of hard drive, perhaps a few other things, (I had found tips on ProTools website for its issues, so decided to try same, cant say for sure but seems to have helped). 
Still on Win7 on my DAW PC though, maybe Ill finally switch it to Win10 despite not liking interface, or change in general.
 
Best of luck, Cheers   

I've sort of got the same system specs as you and the 18i20 and find things extremely stable now under win10, so agree that would be a good move. But it sounds like you have multiple melodyne regions within your project, and that brought me down in a big way until I bounced everything to clips. Save as a new project and try that if you havn't already. Also clean up your drive of temporary files. Feel for you. Trying to get a project finished with glitches happening stopping your workflow is just crap. Someone here will get you going.