Old Session wont open OTT on new Computer [Win 10 to Win 11, Reaper]

Started by ackermax


Pretty much what the title says, have a new PC but my old sessions in reaper wont load the OTT instances for each session. Replacing it with OTT, which is available in the fx settings, does sadly reset the plugin settings to default / init.

Old computer [Win 10] used OTT v1.34 while the new one [Win 11] uses the recent v1.37 OTT.

Other plugins load just fine (ranging from Arturia to Kontakt, etc.).

Quick fix could be to install the v1.34 OTT on my new machine, but couldnt find it anywhere!
I've seen a few other posts like that but no fix so far.



Quick fix was to copy the old "OTT.vst3" file to my new Computer, which fixed the issue. But would be great to be able to use the new versions aswell :)


Sorry to hear it, 1.34 was the first VST3 (it made sense to start with a freeware release), and sure enough something was wrong but not caught in testing, there was a VST3 GUID issue - which I addressed quickly in 1.35.

However that shouldn't make the params go missing. It's quite possible Reaper has a bug there, as OTT is chunkless (just automation parameters) which is a fairly uncommon scenario in VST plugins. It doesn't make complete sense to me for the plugin to load but without the settings.

My recommendation (as it is beyond my control to fix) would be to finish the projects and perhaps archive the 1.34 version with the project data. Or for more ongoing projects perhaps screenshot and replace/recreate with the 1.37 VST3.


Hey Steve, thanks a lot for the quick answer! Yeah figured it could be something about the VST 3 update and Reaper, anyway its not too much of an issue for now as the 1.34 is working for old projects. I'll probably follow your recommendation and update it by hand for each instance. That being said, there is now archive for older OTT versions? Could be a quick fix if people have the same issue as I do.


I don't have anything public-facing as I really don't want older versions of OTT circulating more than needed (for the reason you're facing).