Problem with VSTs in Synfire

I'm now thinking this problem started after Synfire hung and wouldn't allow me to quit. So I did an "End task" to get out of Synfire. 

Is it possible that this damaged the program? If so, might I need to do a fresh install? Would doing so mean I'm starting from square one, or would I retain my preferences etc?

Can you provide specific instructions on how to uninstall and reinstall the Audio Engine?

For starters, I don't know where to find the AudioEngine.msi file so I can reinstall it.

Also, I generally don't use relative filenames, so I doubt that's the issue.

Thanks.

I've now uninstalled and reinstalled Cognitone Audio Engine.msi, but the problem persists. Every VST I've checked is dysfunctional. 

I think my next step is a full uninstall/reinstall of Synfire.

I rightclicked on the audio engine file, then chose Properties, then the Security tab. All permissions show as Allow.

Also, I tried running the program as an Administrator, but again, the problem persists.

I'm going to check a Kontakt forum to see if anyone else has run into this problem. But it's not just Kontakt...it's every VST I've tried.

If it's a file access issue that has nothing to do with Synfire, why can I access the files (VSTs) within Cubase, but not within Synfire?

To me that sounds like it IS a Synfire issue.

I checked the following VSTs in Synfire:

Kontakt 6 - Of the Kontakt instruments I checked (~10), all except Riff Generation seem to display properly. However, none of them will produce sound. There is a new version of Kontakt...Kontakt 7. It's a paid upgrade, which I have not yet purchased. Also, Kontakt standalone works fine, even the Riff Generation instrument.

Avenger - Displays properly, no sound.

Omnisphere - Displays properly, no sound.

Falcon - Displays properly, no sound.

Serum - No sound. Also, I cannot depress a key on the virtual keyboard.

OP-X PRO-II - I cannot select a patch. No sound.

Diva - Displays properly, no sound.

All of the above were working perfectly until a few days ago.

All of these VSTs work properly in Cubase 12 Pro, Windows 10.

For lack of a better idea I uninstalled/reinstalled Synfire, but the problem persists. So Andre, you were right about that.

I'm wondering if perhaps it's a Windows issue.

Problem solved, although I have a question that may never be answered.

I recently switched my audio interface over from an RME Fireface UFX to a UAD Apollo x8p. The RME was showing indications that the power supply might need to be replaced, and UAD was running a promo where if I purchased an x8p I would get a Sphere L22 mic for free. I already have an L22 (great mic!), but had been thinking of getting a second one. So the deal was too much to resist.

Previously, when using the RME I found that Cubase would not share the RME's driver with other programs, for example Synfire. So I bought a cheapo audio interface (Focusrite Scarlett 2i2) to use with Synfire. Since this interface would be used for monitoring only, and not for recording audio, I wasn't overly concerned about getting top quality. The downside was that if I was using both audio interfaces simultaneously (ex: running Cubase/RME and Synfire/Focusrite at the same time) I would hear low volume pops and clicks in the background. Annoying but no big deal...I made certain to exit Synfire before actually recording any audio in Cubase, and the pops/clicks were then not present. 

Upon setting up the Apollo x8p, I noticed that I could use it in Cubase and Synfire simultaneously. Wonderful...now I don't need the Focusrite. However, this worked for 3 or 4 days, and then the Synfire problems started. 

Today, at wits end, I reattached the Focusrite and, in Synfire, selected it as the audio interface. Voila! Everything works as it should, even Kontakt/Riff Generation.

So the new plan is somewhat similar the old plan: Cubase/Apollo; Synfire/Focusrite.

I've also considered working in Synfire/Apollo up to a certain point and then switching over to Cubase, but Cubase is apparently reluctant to release the driver even if I've exited Cubase, and thus the Synfire problems return. I think Cubase might have an option to release the driver when Cubase is in the background, in which case I will try running both programs off the Apollo once again.

The heretofore mentioned unanswered question: Why did the Apollo work on both programs simultaneously for a few days? 

Thanks to Andre and all who offered their assistance.

Because the broken UI problem cleared up at the same time as the "no audio" problem, and the only change I made was to start using a second audio interface, I'm assuming the driver issue (can't use one audio interface in 2 programs) was the cause.

Apparently I'm not out of the woods yet.

When I start playback in Synfire, I immediately hear stuck MIDI notes. Hitting the panic button solves this, but the program then freezes. It's totally unresponsive.

Synfire is also very slow to load.

These problems may or may not be due to the fact that I did a reinstall.

Update: The "stuck note" is there even BEFORE I start playback. I even rebooted the computer, and upon restarting Synfire it's still there.

I've experienced this previously, and it turned out to be a hardware synth with a stuck note. However, my hardware synths are turned off. I've also muted all instruments in Synfire.

I've reverted to an earlier version of my project, and the stuck note is gone. So apparently the problem was specific to that one file (knock on wood).

Another mystery of the universe.