[CURRENT ISSUE] Sims 4 already running
Overview
jump to: Workarounds
This is a common error that is usually caused when Sims 4 cannot access the user folder in Documents > Electronic Arts. It can also be triggered by outdated or otherwise broken mods or custom content.
This guide is only for this specific error in Windows. If you're seeing the error on a Mac, please use this dedicated Mac thread. If you have a different problem, please create your own thread in the appropriate tech (PC, Mac, Console) forum, or the Game and Mod/CC Issues forum.
These workarounds are listed in order from simplest to most complicated, to avoid anyone doing more work than is necessary. If you've already tried one, or it doesn't apply to you, move on to the next step.
jump to: Pause Onedrive syncing
jump to: Remove mods
jump to: Clean user folder
jump to: Temporarily disable antivirus
jump to: New Windows account
jump to: Move/restore location of Documents
jump to: Reset permissions for Documents
jump to: Virus scan
OneDrive can lock up the Sims 4 user folder, or any folder it's automatically syncing, for various reasons. The easiest way to diagnose this is to temporarily pause syncing. Right-click the cloud icon in the lower-right corner of the screen to see the option:
If this helps, the underlying issue is OneDrive, and you may want or need to adjust your settings accordingly. You can choose which folders to sync, stop OneDrive from syncing your Sims 4 folder or all of Documents automatically, or get rid of OneDrive entirely. Please see this guide, specifically the "I don't want OneDrive to sync my files" and "I want to get rid of OneDrive" sections, for further help:
It's as simple as that: Move the Mods folder out of Documents > Electronic Arts and onto the desktop, and delete localthumbcache.package. If this works, something in the Mods folder is the problem. Look for updates to your mods, especially after a patch; or use the 50/50 method to sort through the files in the Mods folder.
https://modthesims.info/wiki.php?title=Game_Help:Finding_Problem_Custom_Content#The_50.25_Method
Keep in mind you may have more than one broken mod or cc item, so be sure to test every file at least once.
Testing with a clean user folder, otherwise known as a factory reset, means temporarily removing all user data. This ensures that nothing from your existing folder is preventing Sims 4 from loading. Move the entire Sims 4 folder out of Documents > Electronic Arts and onto your desktop. If it copies instead of moving, or you get an error when trying to move it, please see the OneDrive section above.
Otherwise, when you launch the game, if it launches, a clean folder will spawn with no content. Your saves and other content will be intact in the folder you moved but temporarily not read by the game. Don't add anything to the new folder yet; just see whether you can get far enough to start a new save.
If this works, you can start moving your content from the old Sims 4 folder to the new one, testing each time to make sure the game still loads. In each case, please move the files only, not the folder they're in, for example move the individual Tray files, not the entire Tray folder. Where the game has created a new file or folder, it's best to use that rather than your old copy. For further reading about the contents of the user folder and what you might want to preserve, please see this:
https://sims4.crinrict.com/eng/2014/09/user-files-explained/
While moving over your data, if and when you see the "already running" error again, you'll know that one of the files you just moved is the problem, and you can split and retest that batch until you find out which one. For mods and custom content, the 50/50 method can make the process much more efficient. A single file or folder that prevents the game from launching is not recoverable; you'll need to delete it, or in the case of mods or cc, find an updated, compatible version.
Disable antivirus (TEMPORARILY)
An overzealous third-party antivirus or even Windows Defender can block Sims 4's access to its user folder. To test this theory, temporarily disable any third-party antivirus, just long enough to try to open Sims 4. As long as you're not doing anything else at the same time, your computer should be safe.
If this helps, set exceptions for TS4_DX9_x64.exe (if using DirectX 9) and/or TS4_x64.exe (if using DX11) as well as EADesktop.exe. You can find a more detailed guide for your specific antivirus in the online documentation provided by the publisher of the software.
For Windows Defender, the only potential problem is with Controlled Folder Access. Please see this post for instructions on changing its settings or disabling the feature entirely:
https://crinrict.com/blog/2019/03/windows-10-defender-controlled-folder-access.html
It's possible that the problem is caused by a setting or broken permissions in your main Windows account, and the fastest way to test this theory is to create a new account. It must have admin rights (not a standard user account), and it must be local, as in, not connected to your Microsoft account.
To create a new account, open Windows Settings > Accounts > Family & other users, click "Add someone else to this PC" (under Other users, not Your family), click "I don't have this person's sign-in information," then "Add a user without a Microsoft account." Choose the username and password, answer some security questions, and you'll see the new account. Click it and select "Change account type" to make it an Administrator account if it's not already. It should say "Administrator - Local account" when you're done:
Click ctrl-alt-delete, select Switch user, and sign into the new account. Then open the EA App (and Steam or the Epic launcher if applicable) and try to launch Sims 4. You shouldn't need to reinstall anything. Your saves and other user data won't be available, but that's fine for the purpose of this test.
If Sims 4 works in the new account, it means the problem is contained to your old account. You can simply continue playing in the new account if you want. For any saves or other user data you'd like to transfer to the new account, sign into the old account again and copy the relevant files to C:\Users\Public. This folder is accessible from all user accounts; you can grab the files from there once you're in the new account.
If you'd like to try to fix your old account, please see the next two sections.
Move or restore location of Documents
If Windows has placed the location of Documents somewhere Sims 4 can't access properly, you may need to move the folder. To find the current location, search in Windows for Command Prompt, open it, and enter this command:
reg query "HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders" /v "Personal"
This will return the full file path to Documents. Unless you've chosen a custom location, it should be one of these, depending on whether OneDrive is involved:
C:\Users\[username]\Documents
C:\Users\[username]\OneDrive\Documents
If you see a different location, one you didn't intend to use, changing it may help. If Documents is in OneDrive and you don't want it there, the best course of action is to tell OneDrive to stop syncing your files, as described here:
If this doesn't successfully change the location, or your Documents directory is in a different unintended location, you can change it by editing your computer's registry. Be very careful when editing the registry—an error can cause problems up to and including preventing your computer from working at all. So please follow these instructions exactly, and don't touch anything other than the Personal value:
Important: This process is only for moving Documents to another location on an internal drive. DO NOT move Documents to an external drive. If you would like to store your Sims 4 user folder externally, please use this guide instead.
Important: Please also keep in mind that when you change the location of Documents, you also change the location where Sims 4 looks for its user folder. You will therefore need to move your saves and other user files to the new location.
Reset permissions on Documents folder
When Sims 4 works in a new Windows account but not your existing one, the problem may be broken permissions in the old account. You can use the takeown command to reset the permissions on the Documents folder if necessary. First, move the Electronic Arts folder out of Documents, or delete it if it's empty. Search in Windows for "Command Prompt," open it, and enter this command:
reg query "HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders" /v "Personal"
The location you see is what you'll use for the command. The command itself is this:
takeown /F "[file path to Documents folder]"
So it will probably be one of these, but double-check anyway:
takeown /F "C:\Users\username\Documents"
or
takeown /F "C:\Users\username\OneDrive\Documents"
Write your actual username for this Windows account (your main one) instead of username. Since the syntax needs to be exactly right, please copy this command to a Notepad file, substitute in your username, and then copy that string when you're ready to use it. Hit Windows key-X and choose either "PowerShell (Administrator)" or "Windows Terminal (Administrator)," whichever option is offered, paste the command into the window, and enter.
Then restart your computer and try again to play.
If that doesn't help, please see this post for further troubleshooting:
You'll of course apply these steps to the Documents folder your account is using, wherever Command Prompt told you that was.
If none of the other troubleshooting steps help, or one of them helps temporarily but Sims 4 stops working again, before you've added back any content or made any other changes that would account for this, your computer may have a virus or other malware. So it's worth running a virus scan. Download Malwarebytes (the free trial is fine) from here:
https://www.malwarebytes.com/mwb-download
Open it, click Scan > Custom Scan > Configure Scan, check all the boxes both for all scan types and for all your drives, and let it do its job. This could take anywhere from a few minutes to several hours, depending on the amount of data and whether the scan finds anything, so you may want to set it to run while you're doing something else. The Malwarebytes report is simple to understand if it doesn't find anything, but if you'd like me to take a look, feel free to reply to this post and attach the report.
If none of this makes a difference, please post in this thread asking for further help. Let me know whether you can play in the new admin Windows account or not: this is important diagnostic information.
