What is the problem? MacOS has a security feature called Gatekeeper. We noticed that it kept stopping crowdrender from working, period. The reason is that when you download Blender, and then extract Blender's files, it is marked by your operating system as to be put in quarantine. This has now been fixed in the pre-release version of 0.1.2. Installing this version (e-mail us for a copy if you are happy to test it :) ) will fix this issue. What OS versions are affected? As far as we can tell, every version of Sierra is affected, we've tested from 12.1.0 up to 12.1.2. Its possible El Capitan is affected but we did not test this explicitly and we haven't rolled back to check this yet. How can I tell I have this problem? Crowdrender would not connect to other machines. To verify if you have this issue, open blender and then choose the scripting screen layout from the menu at the top of the screen. Then enter the following command: bpy.utils.script_paths() You will see a result similar to below, note the unusual path for blender's script paths: /private/var/folders/h8/*some_long_hexadecimal_number/T/AppTranslocation/*more_long_hexythings*/d/blender.app The blender.app is what you requested to run when you opened blender, so why is it running in some weird folder? Welcome to quarantine, if you see this result (especially the "AppTranslocation" words in the paths) you have just confirmed gatekeeper has quarantined blender. Can it be fixed and if so how? If you are comfortable using terminal and typing some commands, you can permanently un-quarantine blender. Here's how to do it. Open terminal from launchpad>utilities You'll need to cd (command to change directory) to where you unzipped blender. On my machine I put the unzipped blender in my downloads folder. You can see below that I first used the cd command to get to my downloads folder. In the image above, I used the "ls" command to show the files in my downloads folder and I can see that the unzipped blender is there. I then use cd again to enter my blender's folder (and wish that I had renamed it so it didn't have the date and time of extraction). Now I can use the xattr command to see if the OS has marked blender as quarantined. xattr shows the execution attributes for blender.app (that is the icon you click on to launch blender). You can see that it has one attribute: com.apple.quarantine. We can remove this with one command and blender will now run from the location you unzipped it and crowdrender will work! The command to run is xattr -d -r com.apple.quarantine blender.app (see above). This tells the OS to delete (-d) the com.apple.quarantine attribute from blender.app and to do this recursively (-r) throughout the blender package. Now try running blender again. In blender, once again, open the scripting screen by using the drop down menu at the top of the user interface and then type: bpy.utils.script_paths() You should see that blender is now referring to the location where you unzipped it rather than the weird location before we removed the com.apple.quarantine attribute. This means that crowdrender will now (hopefully) work. Note, now you have removed this attribute, it will not come back again for this particular copy of blender, but if you download a new copy of blender and attempt to use it, it most certainly will happen again. At this time, we're not sure if this is an issue with blender or gatekeeper. Either way it doesn't look like placing blender in quarantine is intentional by either of those parties, its likely that no one has realised yet since it really doesn't affect blender, only poor old us!