Incredible slowness once upgrading to latest Mac OS

This is the first time I opened Unreal Engine and Xcode since updating to the latest macOS and my whole machine becomes really unresponsive.
I’m seeing a bunch of the following errors in Xcode being repeated quite frequently.

016-10-02 15:54:43.974359 UE4Editor[2792:305730] Trying to add a bogus certificate
2016-10-02 15:54:43.976225 UE4Editor[2792:305730] An error occured while inserting an untrusted certificate into the chain
2016-10-02 15:54:44.188476 UE4Editor[2792:305730] Pruning certificate chain to 18446744073709551615

I’m guessing this has something to do with the slowdown. Has anyone else seen this? Any idea how I can fix it?

Using:
Unreal 4.11.2
Xcode: ver 8.0
Mac OS Sierra 10.12
27" iMac late 2012 24 GB

hi, do you still have this problem? i was just considering updating to sierra

cheers

Yes, I’m still having this problem. I also found this build issue

Setting up Mono
Building UE4Editor…
Compiling game modules for hot reload
Compiling with MacOSX SDK 10.11
ERROR: One or more of the modules specified using the ‘-module’ argument could not be found.
Command /Users/Shared/UnrealEngine/4.11/Engine/Build/BatchFiles/Mac/RocketBuild.sh failed with exit code 5

This was all working just fine before I upgraded…

thank you, think ill hold off for a while. Have you tried reinstalling the engine after updating the OS?

I have this too, and I was already running macOS Sierra when installing Unreal Engine.

While troubleshooting this, I found my machine was really slowing down when I just had Xcode with my file open - even without the Unreal Engine running.
Tor, did you happen to notice if Xcode was running fine after you installed Sierra but before you installed the Engine?