No folder write permission on OSX & Linux
MacBook Pro 2016 Touchbar: I created a folder in my applications called 'addon' and put your file in there. I then pressed the button in blender and this came up in red:
Traceback (most recent call last): File "/Users/strnd/Library/Application Support/Blender/2.78/scripts/addons/filmic_blender.py", line 57, in execute os.rename(cmpath, opath) OSError: [Errno 30] Read-only file system: '/private/var/folders/n7/fhpx1n852sdg_xfzn02zm2jwmxt2vm/T/AppTranslocation/183AF043-928A-4D34-91DD-BF40165F1961/d/blender.app/Contents/Resources/2.78/datafiles/colormanagement' -> '/private/var/folders/n7/fhpx1n852sdg_xfzn02zm2jwmxt2vm/T/AppTranslocation/183AF043-928A-4D34-91DD-BF40165F1961/d/blender.app/Contents/Resources/2.78/datafiles/colormanagement_old'
location:
Traceback (most recent call last): File "/Users/strnd/Library/Application Support/Blender/2.78/scripts/addons/filmic_blender.py", line 57, in execute os.rename(cmpath, opath) OSError: [Errno 30] Read-only file system: '/private/var/folders/n7/fhpx1n852sdg_xfzn02zm2jwmxt2vm/T/AppTranslocation/183AF043-928A-4D34-91DD-BF40165F1961/d/blender.app/Contents/Resources/2.78/datafiles/colormanagement' -> '/private/var/folders/n7/fhpx1n852sdg_xfzn02zm2jwmxt2vm/T/AppTranslocation/183AF043-928A-4D34-91DD-BF40165F1961/d/blender.app/Contents/Resources/2.78/datafiles/colormanagement_old'
location:
Sounds like a problem with the folder permissions, but since I don't have a Mac to test with I don't think I can solve this now.
I have the same problem with Ubuntu 16.04. Here is a screenshot:

I guess in linux it has to be run with sudo, unless you store blender somewhere that you have permission to write to
Pity! I want the ease of updating so badly
Did you install blender from one of the linux package managers (apt-get)? Those are usually problematic for a variety of reasons. Better to get it from blender.org or builder.blender.org.
Removed add on and move blender out of my applications folder and into documents. Added add on again and keep getting this:
Traceback (most recent call last): File "/Users/strnd/Library/Application Support/Blender/2.78/scripts/addons/filmic_blender.py", line 57, in execute os.rename(cmpath, opath) OSError: [Errno 30] Read-only file system: '/private/var/folders/n7/fhpx1n852sdg_xfzn02zm2jwmxt2vm/T/AppTranslocation/06C28B33-B209-4B2F-9E8D-779EFA3AF4CD/d/blender.app/Contents/Resources/2.78/datafiles/colormanagement' -> '/private/var/folders/n7/fhpx1n852sdg_xfzn02zm2jwmxt2vm/T/AppTranslocation/06C28B33-B209-4B2F-9E8D-779EFA3AF4CD/d/blender.app/Contents/Resources/2.78/datafiles/colormanagement_old'
location:
Read-only file system? I have Sophos installed on system but can't see how that would be an issue with permissions.I'm not sure how I can fix this. Any suggestions as I think your add on is a great way to update Filmic on Blender and I would like to say thank you for the time to make this add on.
For Linux users, just start blender from a terminal with sudo blender, then it'll have permission to write to that folder. No idea what the sudo equivalent for OSX is.
It's sudo 😁
Isn't there another way? Can't you open a password prompt or something?
No idea, someone with experience with this should help out.
The easiest way to adjust on Linux (and mac) is to use the environment variable approach:
"export OCIO=/path/to/where/the/filmic-blender/config.ocio" So put export OCIO=cpath or something similar in the code and all will be well for both mac and linux.
See the discussion about the environment variable here: https://github.com/sobotka/filmic-blender
That should be modifiable without sudo etc
I ran into the same issue on Windows 10 today. It's in a different line though.

Edit: Found a solution and its the same as on another OS: run as administrator.