_This is a shorter version without changing the limit.maxproc values derived from the original gist.
Please take a look at https://gist.github.com/tombigel/d503800a282fcadbee14b537735d202c before doing anything from this gist
I removed any explenation from this and I also removed the changes to limit.maxproc
For more information about the existence of this gist please look here: https://github.com/dredhorse/SnowWhite/blob/master/this-and-that/unable-to-update-cities-skylines-in-macos-catalina.md
Warning: This might leave your computer in an unusable state if anything goes wrong. In that case boot into recovery mode and remove /Library/LaunchDaemons/limit.maxfiles.plist from you bootdisk. That is not the / you have available in recovery mode!
Unload Daemon
sudo launchctl unload -w /Library/LaunchDaemons/limit.maxfiles.plist
Change value in /Library/LaunchDaemons/limit.maxfiles.plist
Load Daemon again, to make sure reboot.
sudo launchctl load -w /Library/LaunchDaemons/limit.maxfiles.plist