Hello, I just stumbled upon a bug (which admittedly took me some time to pinpoint).
I added instances to a project using Rainer’s Insert Instances script. This also (optionally) adds Axis Location custom parameters to all masters and new instances. The values are automatically set for the intances. For the masters, they are left empty. When I now try to save the file, I get an “Unrecognised selector sent to instance” error. It is impossible to save the file before removing the newly added instances, or setting the axis location in the master custom parameters.
Just something that I doubt is intentional 