Hi-

Thank you for the additional information. What version of Tverb are you using? Did you install any software, update your OS, change your auido interface settings, anything between when these issues happened and when they last worked?

Regarding session 1, if you could find the exact error number that would be very helpful. You could also try the steps outlined in this article: https://support.apple.com/en-us/HT204466

Are session 1 and 2 at the same sample rate? Are they using the same buffer sizes? Basically, what are the differences in how you are using Tverb between the two…