external drive

@beachedwhaale  This isn't typical behavior; it seems like something is tripping up the EA App.  Do you have the App set to start with Windows?  If so, try disabling that and only opening the App when your external drive is already plugged in.  Additionally, after closing the App, kill the EABackgroundService in the Task Manager before disconnecting the external drive.

When the App doesn't see Sims 4 as installed, you can try reinstalling it to the same location.  The App may simply verify the files and finish the install process rather than downloading everything from scratch.  This has usually worked for me during testing.

Additionally, make sure the external drive always receives the D letter, that you haven't first plugged in anything else that's been assigned D.  And if you use a third-party antivirus, set exceptions for TS4_x64.exe and EADesktop.exe.