Hi boomer,
Welcome to GimpChat!
The very, very specific problem is a parsing error during script processing; the G'MIC command, -bilateral takes two numeric arguments. However an error in substitution (cause unknown) is giving this command the string '10,7' which isn't a pair of numbers but three digits, digits two and three separated by a comma and the whole taken to be one string (and not two numbers).
Why should this calamity take place? I could think of a host of reasons, but don't have sufficient particulars for diagnosis, which could be time consuming for both of us. One big area of missing particulars for me is that I'm not (currently) a Mac user. That said, my favorite (untested) theory is that you are suffering from version mismatches among the various pieces of your Gimp, gmic_gimp, supporting scripts and Mac system libraries. In particular, the supporting scripts could be from a different version than gmic_gimp, which could lead to problems of the type you are observing.
I see from your post that you initally installed G'MIC, had troubles, found a Gimp package with G'MIC pre-installed, and that this one (mostly) works, though the smoothing filters don't. I'm wondering if the old installation was completely un-done? That scripts from one version are interacting with a plug-in of another version?
More to the point, your Gimp and G'MIC versions are both somewhat old. The reason why you cannot upgrade to gmic_gimp 1.6.0.0 is that the the latest gmic_gimp binaries link against only the more recent versions of Gimp, and Gimp 2.8.10, I fear, is now out of the support window, which, for a lot of reasons can't be very far back.
For a lot of good reasons, the Mac is very particular about versions being properly aligned. My general suggestion then is to get GIMP, G'MIC and your Mac system libraries properly aligned at the latest versions possible for Lion (10.7.X). A very knowledgeable Mac AND G'MIC person is Karsten, who wrote a general guideline for getting G'MIC running on the Mac - See
gmic on Mac in this forum. There are links following off of that thread that are also useful.
I stress getting the latest versions possible because many new features arrived with G'MIC 1.6.0.0, and some very significant new features are planned for 1.6.0.1. The 1.5.x.x series is rather unbearable to use in comparison. It also makes support from other people somewhat more available, as fewer and fewer use the older versions as time goes by. Finally, you may be suffering from a script bug that was fixed in later G'MIC versions.
You're probably thinking: 'Yeck! a complete uninstall-reinstall?' and, well, yes, I think this is where this is heading. Partha (
Partha's Place) seems to be a reliable integrator of Windows and Mac binaries and takes pains to provide the latest versions. After reading Karsten's guidelines and branching threads, my inclination would be to get binaries from Partha. Do make sure that the uninstall is complete, for it seems that many problems arise when debris from one install interfere with those of another (mismatched libraries and the like).
Hope this helps
Garry