Engine looking for plugin files that are disabled

In my project I used some of the material files on some of my actors from a plugin folder, AllRightRig, but when I upgraded to a newer version of the engine, the plugin no longer works so it’s disabled. Even though I went and removed the material references from the plugin folder and replaced them with different materials, the engine is still thinking that those material files are missing when I try to package the game. I can’t re-add the plugin and I’m not sure what to do at this point. I don’t know where to find that the game is still trying to reference the material files that I’m no longer using.

These are the errors I’m getting:

UATHelper: Cooking (Windows): LogPackageName: Error: DoesPackageExist: DoesPackageExist FAILED: ‘/AllrightRig/Mixamo/PoliceGirl/Materials/Topmat’ is not a standard unreal filename or a long path name. Reason: Path does not start with a valid root. Path must begin with: ‘/Engine/’, ‘/Game/’, ‘/Paper2D/’, ‘/MediaCompositing/’, ‘/OculusVR/’, ‘/SteamVR/’, '/Co
UATHelper: Cooking (Windows): LogPackageName: Error: DoesPackageExist: DoesPackageExist FAILED: ‘/AllrightRig/Mixamo/PoliceGirl/Materials/Topmat’ is not a standard unreal filename or a long path name. Reason: Path does not start with a valid root. Path must begin with: ‘/Engine/’, ‘/Game/’, ‘/Paper2D/’, ‘/MediaCompositing/’, ‘/OculusVR/’, ‘/SteamVR/’, '/Co
UATHelper: Cooking (Windows): LogPackageName: Error: DoesPackageExist: DoesPackageExist FAILED: ‘/AllrightRig/Mixamo/PoliceGirl/Materials/Topmat’ is not a standard unreal filename or a long path name. Reason: Path does not start with a valid root. Path must begin with: ‘/Engine/’, ‘/Game/’, ‘/Paper2D/’, ‘/MediaCompositing/’, ‘/OculusVR/’, ‘/SteamVR/’, '/Co
UATHelper: Cooking (Windows): LogPackageName: Error: DoesPackageExist: DoesPackageExist FAILED: ‘/AllrightRig/Mixamo/PoliceGirl/Materials/Topmat’ is not a standard unreal filename or a long path name. Reason: Path does not start with a valid root. Path must begin with: ‘/Engine/’, ‘/Game/’, ‘/Paper2D/’, ‘/MediaCompositing/’, ‘/OculusVR/’, ‘/SteamVR/’, '/Co
UATHelper: Cooking (Windows): LogPackageName: Error: DoesPackageExist: DoesPackageExist FAILED: ‘/AllrightRig/Mixamo/PoliceGirl/Materials/Topmat’ is not a standard unreal filename or a long path name. Reason: Path does not start with a valid root. Path must begin with: ‘/Engine/’, ‘/Game/’, ‘/Paper2D/’, ‘/MediaCompositing/’, ‘/OculusVR/’, ‘/SteamVR/’, '/Co

Hi, I’m having exactly the same issue here. Have you ever solved this?