Re: Sims 4 keeps crashing on launch after installation of dlc

@Phi_Phantastic  Please do a clean uninstall and reinstall of both the game and the EA App.  Start with Sims 4:

• Put aside your Sims 4 folder in Documents\Electronic Arts and rename it to something that doesn't include the words "Sims 4."
• Download Revo Uninstaller (the free version is fine) from here.
• Launch Revo, select Sims 4 from the list, and click Uninstall.
• Cancel the system restore point; you don't need it.
• Once the game is uninstalled, select "Moderate" under "scanning modes," and click Scan.
• Review the list, in case there's something you want to save; otherwise, click Select All, and then Delete.
• Close Revo, and restart your computer.

For the EA App:

• Launch Revo, select the App, and click Uninstall.
• Cancel the system restore point.
• The EA App may open a window.  Click Uninstall, then in the Revo window, click Moderate under Scanning modes, and click Scan.
• Revo will present a list of registry entries.  Click Select All, then Delete: you don't need or want to preserve these entries.
• For the leftover files and folders, click Select All, review the list and deselect anything you'd like to keep (this is unlikely, but it's worth checking), click Delete, and you're done.
• Close Revo, and restart your computer.

Install the EA App, then create a new folder into which you'll install Sims 4.  The folder should be on the root level of the drive of your choice, for example C:\Games is fine, but not C:\Program Files\Games.

While reinstalling, please disable any third-party antivirus you use, or disable Controlled Folder Access if you only use Windows Defender.  Don't reenable it until after testing Sims 4 at least once.  If that helps, set exceptions for TS4_x64.exe and EADesktop.exe.  As long as you don't do anything else at the same time, your computer should be safe.