C3 hangs switching between songs that use Overloud TH-U (SOLVED)


Thanks to a couple posters here, I found and love the Overloud TH-U guitar amp sim. I just a noticed a problem using it in C3, however. Has anyone else experienced this?

If I switch from one song that has the TH-U plugin in a rack to a different song that also has an instance of the TH-U plugin in a rack (different rack, different instance of the plugin), then after C3 loads all of the plugins for the 2nd song, it hangs - just before it renders the main window for the new song.

I THINK I have narrowed it down to this plugin. I tried going back from C3 version 3590 to 3589 - no change. The other possibility that could be contributing to this is that I recently updated by Windows 10 to the May 2019 update. But this is the only time I am noticing a problem going from one song to another. (I tried other transitions where 2 instances of the same plugin are used, with no problems. But I haven’t tried every single plugin yet.)


I am using TH-U. No problems here.



Just curious…why are you not using one rack, with different instances within that rack, instead of using multiple racks of the same plug?



Corky, good question. Mainly because of the way I started creating songs and racks, and then being too lazy to change.

I basically created a distinct rack for each different “sound” or “patch” (which might consist of multiple plugins - both instruments and effects), and haven’t used rack states very much.

So I have 3 different racks that use TH-U for example, all of which produce a guitar-like sound. In one rack, it might be an EP routed through TH-U (Marshall sim) for power chords; in another I have a Strat-like patch in Omnisphere routed through a Fender-like amp sim in TH-U; another rack i route a lead synth sound through a AC30 sim to get a mildly distorted, bright “singing” lead sound.

Other examples too. But I have’t tried to consolidate those multiple instances of TH-U into one rack. (Similar story for other plugins). I realize that this approach is not very efficient, but I find the approach easy to use and very flexible in terms of getting just the sound I want in each rack/song.

Sorry for the rambling. But I hope it helps explain my setup.


Hey Roland

I understand your approach, as I do much the same thing with a new VST until I feel comfortable with it’s features.

Did you use C3 Profiler to see which plug is hanging?


Not yet. I will be doing more troubleshooting. I just noticed it earlier today before our rehearsal


So here’s what I have found after a little more trial and error:

The Profiler was not any help since the issue causes C3 to hang, including the Profiler.

I noticed with Verbose Logging turned on that, in most cases, when I switch from one song to another, even if I have different instances of the same plugin in both songs, I see log entries like:
VST Plugin- Omnisphere (0x000000001F03E6C0) - Stopping processing…
VST Plugin- Omnisphere (0x000000001F03E6C0) - Stopped processing
… and a little later …
VST Plugin- Omnisphere (0x000000001F03E6C0) - Closed
But with TH-U, if I go from one song to another where both songs have instances of TH-U (different presets), C3 never gets to the VST Plugin- TH-U - Closed entry.

I removed Racks from the equation by creating 2 very simple songs with nothing but an instance of TH-U in each song. I did similar experiments with a few other plugins (Omnisphere, PianoTeq, a couple Waves fx plugins). None experienced the same issue. I am suspecting that this is a case of TH-U not shutting down each instance in the right way, but I can’t really prove it.

But a question to @brad, if this is indeed what’s happening, is there anything I can do to force C3 to handle this without hanging? Or do I need to try to work with Overloud? Or perhaps rethink my Song/Rack strategy, as Corky has hinted?


I am consistently able to repro this problem with TH-U “on my machine”, but I would appreciate if someone could try this on their machine, I am uploading 2 nearly identical songs with nothing but an instance of TH-U. I don’t even need a VSTi to produce a sound to trigger the problem. If I first load one of these songs, then switch to the other (File | Open Song…), C3 just hangs.

If I open a different song with no TH-U and then open the 2nd song, no problem. Also, if I stop the C3 Audio Engine while switching songs, again no problem.

Thanks in advance if someone can validate this…
TH-U-1.cantabileSong (8.2 KB)
TH-U-2.cantabileSong (8.2 KB)


Roland, I am 75 miles away from my rigs, but will be glad to check it out when I get back.



I downloaded and used your 2 songs. It is normal switching here…no hang on C3. The presets switched perfectly. These, of course, were not in a rack, so that didn’t matter.
Also my routing out was the simple “main speakers”, and I used no input route. Are you using more complicated routing (just a guess out of the blue)? That is where I personally would go next, or maybe remove/re-install TH-U.



Thanks for the confirmation. Maybe I’ll try uninstalling/re-installing TH-U. Even this simple setup hangs for me.


I think I figured it out. I downloaded and installed the latest version from Overloud, and realized that I jumped from version 1.0.5 to 1.0.13. Not necessarily saying there was a bug in the older version, but something was apparently fouled up with my PC.) In any case, I do not have any issues after installing this version.

Thanks again Corky for helping me eliminate different options and narrow in on the answer.


No prob Roland…glad you got it going. :sunglasses: