Issue with spectral layers file extension N12

I had recorded a number of acoustic guitar songs for a client last week, meanwhile I had gone in and done some spectral layers editing (removing click bleed) and I had not rendered (made permanent) the edits yet

This week, the client came back to add some more songs, so I set up the same and record enabled on the same tracks later in the session

Had huge problems, audio out of sync, waveforms not drawing, record light not coming on during recording and so on. while N12 didn’t actually crash, it was acting like it had.

Opened the session in N11, same thing, booted into a week ago OS install, same thing. nothing fixed it until…

I either removed or rendered the spectral layers editing I had done on the earlier songs in the session on the same track.

This may or not be an issue with spectralayers or the nuendo extension system itself