Apple obviously forgot to add libnfshared.dylib for whatever reason in the final version of Xcode 12 for iOS 14 simulators. A working workaround until Apple fixes this is to copy the missing lib from Xcode 12 beta 6 over (download the beta from Apple’s developer download section). The missing lib can be found here and must go into the same directory for final Xcode 12
This works for me.
If you want to avoid the hassle of downloading 11.25GB Xcode 12.2 beta for a single file. I have the file to share.
You may execute the following command to download and place it inside the Xcode package:
sudo curl https://storage.googleapis.com/mobile-simulator-build/libnfshared.dylib -o /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/usr/lib/libnfshared.dylib