On Mac OS, SAM stores its application files in the following folder:
.../SAM.app/Contents/MacOS/exelib
For example, the weather data files are in the following folder
SAM.app/Contents/MacOS/exelib/climate_files
When you use the TMY3 Creator, the first step is to open a "base TMY3 file," but when you try to do that on a Mac, SAM looks in a different folder that causes an error. To work around this problem, copy the TMY3 file(s) you want to use as the base file from the climate_files folder to a new folder that you can easily find. Then on the Climate page, click Add/Remove, and add the folder to the list of folders SAM searches for weather files. Now when you use the TMY3 Creator, load the base TMY3 file from that folder instead of the default folder that causes the error.
Similarly, the libraries are stored in .samlib files in the following folder
SAM.app/Contents/MacOS/exelib/libraries
To modify a library, first copy its .samlib file to a folder you can find, and then use the Library Editor to navigate to that copy of the file.
I realize those instructions may be confusing, so please let me know if you need clarification.
Best regards,
Paul.