MultiMC

Do NOT disable "API" or "library" mods, because the other mods need them.

Instructions vary depending on whether you had installed FO on MultiMC with the easier installation or with automatic updates.

Windows

Tutorial by Ultrasonic1209 based on Remty5's workaround.

1. Open MultiMC

2. Right-click on Fabulously Optimized

3. Click on the Instance Folder button

4. While holding ⇧ Shift, right-click inside of the folder

5. Click on Open in Terminal or Open with PowerShell or similar

6. Run the following commands to download the scripts that will disable the mods:

   (Invoke-WebRequest -Uri "https://raw.githubusercontent.com/Fabulously-Optimized/fabulously-optimized/main/Packwiz/pre-launch.ps1" -OutFile "pre-launch.ps1")
   (Invoke-WebRequest -Uri "https://raw.githubusercontent.com/Fabulously-Optimized/fabulously-optimized/main/Packwiz/post-exit.ps1" -OutFile "post-exit.ps1")

   This should download two files: pre-launch.ps1 and post-exit.ps1

7. Open pre-launch.ps1 in a text editor. You should find a list of mods starting on line 4

8. Copy the name of the mod you want to disable

9. Paste the name of the mod in the line you found in step 7

10. Disable more mods by adding them under line 4 with the same format

11. Go back to MultiMC

12. Click on Fabulously Optimized

13. Click on Edit Instance

14. Replace the pre-launch command with the following:

powershell -ExecutionPolicy Bypass -File ..\pre-launch.ps1

1. Replace the post-exit command with the following:

powershell -ExecutionPolicy Bypass -File ..\pre-launch.ps1

Linux and macOS