Guitar Rig stopped working - returns audio error

[henrod]

I missed that you were running Catalina. According to NI:

macOS 11, 12 or 13 (latest update)

I don't see anything for GR 6 on the Legacy Updates page, only GR 5:

...

I think I found the issue over in the NI Support boards.

Native Access has been updating many VIs to versions that require Kontakt 7.6 even if the users do not have it or their OS cannot run it. So far, the answer is to be running K 7.6 — which misses the point completely. There are links for rolling back many VIs to earlier versions but I don't see that Guitar Rig is on those lists. They do recommend yuu contact Support if you fall through the cracks.

Lots of handwringing and opinionizing that NA shouldn't have to be expected to make this distinction.

Funny—Microsoft Auto Update knows to give an error message if your OS is too old to run the latest updates to Office (as yours is, BTW) and won't install the latest in that case. MS also makes all legacy updaters available for download—as I have a cottage industry maintaining 2012 MacBook Pros, I use that resource a lot. I think every school teacher in the Silicon Valley bought one and the word is out that I know how to fix and upgrade them.

NI got back to me with a link to 6.2.3 (I think... I don't have it in front of me now) and told me that what I'm experiencing is the known bug about running GP6 in mono. So... I'm gonna stick with BIAS FX until I'm ready to upgrade the MacOS, which probably won't be until I buy a new machine.