phrenq

Thanks guys -- I figured it out. While poking around in the plugin source code, I noticed it references the PluginData directory relative to the "saves/<game>/Ships/VAB" directory (i.e., "../../../../PluginData/subassemblyLoader/subassemblies/"). My saves directory is actually a symbolic link to a directory in Google Drive, which I use to sync saves across computers, and this was tripping it up. Even though the error message said it was failing to save the file in the "/Steam/SteamApps/common/KSP/PluginData" directory, it was really trying to save in a PluginData directory that was a sibling of the symbolic link target, in my Google Drive directory. So I made PluginData another symlink in the same location, and problem solved! Appreciate the help.

Yeah, I made all the directories world writable, although that shouldn't be an issue since the KSP process runs as my user. I wonder, has anyone else ever successfully used Subassembly Manager on OSX, and on OSX with Steam?

I don't think that's the problem. It's not really that long a name. But just in case, I moved the steam install location and still got the same exception:

I'm unable to save any subassemblies. On Mac OSX. I can choose a category, enter a file name and hit Save, but get this exception in the debug logs: This path DOES exist on my disk. Any ideas?