Antivirus/Firewall

Both are important and protect you from a lot of evil around the net. They sometimes do block connections and prevent you from up- and downloading things or from updating your software, though.

Because of this, you should add Origin and EA sites/files as an exception to your programs (refer to the manual on how to do that for your product).

The necessary files for Sims 4 can be found here (the path for Origin/EA app can vary depending on your installation)

<Installation folder>\Game\Bin\TS4_x64.exe
<Installation folder>\Game\Bin_LE\TS4.exe
c:\programs(x86)\Origin Games\origin.exe
c:\programs(x86)\Origin Games\OriginClientService.exe
C:\Program Files\Electronic Arts\EA Desktop\EA Desktop\EADesktop.exe

Avast/AVG
Sophos
Windows Defender/Controlled Folder Access