Installing and troubleshooting mods on a Mac is slightly different than it is on a pc.
Mac users can use mods and custom content, but they will need to be gone through from time to time to make sure they are kept up to date. As updates to the game changes the way the game works. Therefore the mods and CC need to be updated.
There's not a lot Mac or PC players can do about that but make sure everything is kept updated.
I am a pc user, so all I can really do is refer you to this thread on the AHQ forum to see if any of it's information will help.
CC Mods and Patching
https://answers.ea.com/t5/Technical-Issues-Mac/READ-FIRST-Sims-4-Mac-Help-Guides-and-Troubleshooting/td-p/4612394#M166If you have any further questions, you might try posting them to the forum linked below.
AHQ's Sims 4 Mac Tech Help Board:
https://answers.ea.com/t5/Technical-Issues-Mac/bd-p/The-Sims-MacSign in with your EA account, click the New Topic button, up near the top of the board, to make a new post.