Editor not building project after changing mipMapBias with TextureImporter.

Problem:
As I was not able to change the mipMapBias inside of the .meta file for my texture myself, I tried using the TextureImporter inside the same file as my GameController GameObject to change it programmatically. This then causes my it to not build and gives the logs as shown below. And the code implementation also shown below.

The TextureImporter is at the bottom of the file in the RoadPostprocessor class.

using System;
using UnityEngine;
using UnityEditor;

public class RoadGenerator : MonoBehaviour
{
    BoxCollider roadBoxCollider;

    public float roadSpeed;

    public GameObject roadPiece;
    GameObject[] generatedRoadPieces;

    float zFullExtent;

    int frontRoadPiece = 0;
    int lastRoadPiece;

    public int numOfRoadPieces;

    Vector3 movementStep;


    // Start is called before the first frame update
    void Start()
    {
        movementStep = new Vector3(0, 0, -10) * roadSpeed;
        lastRoadPiece = numOfRoadPieces - 1;
        generatedRoadPieces = new GameObject[numOfRoadPieces];
        generatedRoadPieces[0] = Instantiate(roadPiece, new Vector3(0, 0, 0), transform.rotation);
        roadBoxCollider = generatedRoadPieces[0].GetComponent<BoxCollider>();
        zFullExtent = roadBoxCollider.bounds.extents.z * 2;
        buildRoads(numOfRoadPieces);
    }

    // Update is called once per frame
    void FixedUpdate()
    {
       
        if (generatedRoadPieces[frontRoadPiece].transform.position.z <= -40)
        {
            recycleRoads();
        }
        moveRoads();
    }

    void buildRoads(int numOfRoads)
    {
        float newZCenter = roadBoxCollider.center.z + zFullExtent;
        for (int i = 1; i < numOfRoads; i++)
        {
            generatedRoadPieces[i] = Instantiate(roadPiece, new Vector3(0, 0, newZCenter), transform.rotation);
            newZCenter += zFullExtent;
        }
    }



    void recycleRoads()
    {
        var endPosition = new Vector3(0, 0, generatedRoadPieces[lastRoadPiece].transform.position.z + zFullExtent);
        Rigidbody frontRoadRigidBody = generatedRoadPieces[frontRoadPiece].GetComponent<Rigidbody>();
        HouseSpawner houseSpawner = generatedRoadPieces[frontRoadPiece].GetComponent<HouseSpawner>();
        houseSpawner.buildHouses(generatedRoadPieces[frontRoadPiece]);
        frontRoadRigidBody.transform.position = endPosition;
        frontRoadRigidBody.transform.position += movementStep * Time.deltaTime;
        if (frontRoadPiece == numOfRoadPieces - 1)
        {
            lastRoadPiece = numOfRoadPieces - 1;
            frontRoadPiece = 0;
        }
        else
        {
            lastRoadPiece = frontRoadPiece;
            frontRoadPiece++;
        }
    }

    void moveRoads()
    {
        foreach (GameObject roadPiece in generatedRoadPieces)
        {
            roadPiece.GetComponent<Rigidbody>().MovePosition(roadPiece.transform.position + movementStep * Time.deltaTime);
        }
    }
}


public class RoadPostprocessor : AssetPostprocessor
{
    public static void Execute()
    {
        TextureImporter roadTextureImporter = (TextureImporter)TextureImporter.GetAtPath("Assets/ModularRoads_v1.02/Materials/UVs/Straight_4-lane/Straight_4-lane_UV-01.png");
        roadTextureImporter.mipMapBias = -0.4f;
    }
}
Build completed with a result of 'Failed' in 1 seconds (1281 ms)
0x00007ff75d2eed7c (Unity) StackWalker::GetCurrentCallstack
0x00007ff75d2f4f29 (Unity) StackWalker::ShowCallstack
0x00007ff75daea823 (Unity) GetStacktrace
0x00007ff75ea1ddaa (Unity) DebugStringToFile
0x00007ff75d48120d (Unity) DebugLogHandler_CUSTOM_Internal_Log
0x0000018ba69dd4cb (Mono JIT Code) (wrapper managed-to-native) UnityEngine.DebugLogHandler:Internal_Log (UnityEngine.LogType,UnityEngine.LogOption,string,UnityEngine.Object)
0x0000018ba69dd2bb (Mono JIT Code) UnityEngine.DebugLogHandler:LogFormat (UnityEngine.LogType,UnityEngine.Object,string,object[])
0x0000018ba69dd000 (Mono JIT Code) UnityEngine.Logger:Log (UnityEngine.LogType,object)
0x0000018e3ad5d645 (Mono JIT Code) UnityEngine.Debug:LogError (object)
0x0000018d7eeefad3 (Mono JIT Code) UnityEditor.BuildPlayerWindow/DefaultBuildMethods:BuildPlayer (UnityEditor.BuildPlayerOptions)
0x0000018d7eeece4b (Mono JIT Code) UnityEditor.BuildPlayerWindow:CallBuildMethods (bool,UnityEditor.BuildOptions)
0x0000018d7eeec943 (Mono JIT Code) UnityEditor.BuildPlayerWindow:BuildPlayerAndRun (bool)
0x0000018d7eeea22b (Mono JIT Code) UnityEditor.BuildPlayerWindow:BuildPlayerAndRun ()
0x0000018d4f4aaffd (Mono JIT Code) (wrapper runtime-invoke) object:runtime_invoke_void (object,intptr,intptr,intptr)
0x00007ffef9fde660 (mono-2.0-bdwgc) [mini-runtime.c:2812] mono_jit_runtime_invoke
0x00007ffef9f62af2 (mono-2.0-bdwgc) [object.c:2921] do_runtime_invoke
0x00007ffef9f6bb4f (mono-2.0-bdwgc) [object.c:2968] mono_runtime_invoke
0x00007ff75d230dfe (Unity) CallStaticMonoMethod
0x00007ff75d230ba7 (Unity) CallStaticMonoMethod
0x00007ff75d7eaedf (Unity) BuildPlayerWithLastSettings
0x00007ff75d53d614 (Unity) MenuController::ExecuteMenuItem
0x00007ff75d53d028 (Unity) MenuController::ExecuteMainMenuItem
0x00007ff75dee6947 (Unity) EditorApplication_CUSTOM_ExecuteMenuItem
0x0000018d7eeea017 (Mono JIT Code) (wrapper managed-to-native) UnityEditor.EditorApplication:ExecuteMenuItem (string)
0x0000018d7eee9f73 (Mono JIT Code) UnityEditor.ShortcutManagement.MenuItemEntryDiscoveryInfo:<.ctor>b__7_0 (UnityEditor.ShortcutManagement.ShortcutArguments)
0x0000018d7eee7ec1 (Mono JIT Code) UnityEditor.ShortcutManagement.Trigger:HandleKeyEvent (UnityEngine.Event,UnityEditor.ShortcutManagement.IContextManager)
0x0000018d7eee72f3 (Mono JIT Code) UnityEditor.ShortcutManagement.ShortcutController:HandleKeyEvent (UnityEngine.Event)
0x0000018d7eee721b (Mono JIT Code) UnityEditor.ShortcutManagement.ShortcutIntegration:EventHandler ()
0x0000018d7eee712c (Mono JIT Code) UnityEditor.EditorApplication:Internal_CallGlobalEventHandler ()
0x0000018d4f4aaffd (Mono JIT Code) (wrapper runtime-invoke) object:runtime_invoke_void (object,intptr,intptr,intptr)
0x00007ffef9fde660 (mono-2.0-bdwgc) [mini-runtime.c:2812] mono_jit_runtime_invoke
0x00007ffef9f62af2 (mono-2.0-bdwgc) [object.c:2921] do_runtime_invoke
0x00007ffef9f6bb4f (mono-2.0-bdwgc) [object.c:2968] mono_runtime_invoke
0x00007ff75d238de4 (Unity) scripting_method_invoke
0x00007ff75d234451 (Unity) ScriptingInvocation::Invoke
0x00007ff75d22e6d5 (Unity) ScriptingInvocation::Invoke<void>
0x00007ff75c56c21b (Unity) Scripting::UnityEditor::EditorApplicationProxy::Internal_CallGlobalEventHandler
0x00007ff75d609c5a (Unity) CallGlobalInputEvent
0x00007ff75db1719e (Unity) GUIView::ProcessEventMessages
0x00007ff75db1122d (Unity) GUIView::GUIViewWndProc
0x00007fff64d6e7e8 (USER32) CallWindowProcW
0x00007fff64d6e229 (USER32) DispatchMessageW
0x00007ff75daf0406 (Unity) MainMessageLoop
0x00007ff75daf4186 (Unity) WinMain
0x00007ff75f654672 (Unity) __scrt_common_main_seh
0x00007fff650a7034 (KERNEL32) BaseThreadInitThunk
0x00007fff65ee2651 (ntdll) RtlUserThreadStart

UnityEditor.BuildPlayerWindow+BuildMethodException: 2 errors
  at UnityEditor.BuildPlayerWindow+DefaultBuildMethods.BuildPlayer (UnityEditor.BuildPlayerOptions options) [0x002ca] in <7ca9a09aeae542ab86253a551b1c89a0>:0
  at UnityEditor.BuildPlayerWindow.CallBuildMethods (System.Boolean askForBuildLocation, UnityEditor.BuildOptions defaultBuildOptions) [0x00080] in <7ca9a09aeae542ab86253a551b1c89a0>:0
0x00007ff75d2eed7c (Unity) StackWalker::GetCurrentCallstack
0x00007ff75d2f4f29 (Unity) StackWalker::ShowCallstack
0x00007ff75daea823 (Unity) GetStacktrace
0x00007ff75ea1ddaa (Unity) DebugStringToFile
0x00007ff75d48120d (Unity) DebugLogHandler_CUSTOM_Internal_Log
0x0000018ba69dd4cb (Mono JIT Code) (wrapper managed-to-native) UnityEngine.DebugLogHandler:Internal_Log (UnityEngine.LogType,UnityEngine.LogOption,string,UnityEngine.Object)
0x0000018ba69dd2bb (Mono JIT Code) UnityEngine.DebugLogHandler:LogFormat (UnityEngine.LogType,UnityEngine.Object,string,object[])
0x0000018ba69dd000 (Mono JIT Code) UnityEngine.Logger:Log (UnityEngine.LogType,object)
0x0000018e3ad5d645 (Mono JIT Code) UnityEngine.Debug:LogError (object)
0x0000018d7eeecebb (Mono JIT Code) UnityEditor.BuildPlayerWindow:CallBuildMethods (bool,UnityEditor.BuildOptions)
0x0000018d7eeec943 (Mono JIT Code) UnityEditor.BuildPlayerWindow:BuildPlayerAndRun (bool)
0x0000018d7eeea22b (Mono JIT Code) UnityEditor.BuildPlayerWindow:BuildPlayerAndRun ()
0x0000018d4f4aaffd (Mono JIT Code) (wrapper runtime-invoke) object:runtime_invoke_void (object,intptr,intptr,intptr)
0x00007ffef9fde660 (mono-2.0-bdwgc) [mini-runtime.c:2812] mono_jit_runtime_invoke
0x00007ffef9f62af2 (mono-2.0-bdwgc) [object.c:2921] do_runtime_invoke
0x00007ffef9f6bb4f (mono-2.0-bdwgc) [object.c:2968] mono_runtime_invoke
0x00007ff75d230dfe (Unity) CallStaticMonoMethod
0x00007ff75d230ba7 (Unity) CallStaticMonoMethod
0x00007ff75d7eaedf (Unity) BuildPlayerWithLastSettings
0x00007ff75d53d614 (Unity) MenuController::ExecuteMenuItem
0x00007ff75d53d028 (Unity) MenuController::ExecuteMainMenuItem
0x00007ff75dee6947 (Unity) EditorApplication_CUSTOM_ExecuteMenuItem
0x0000018d7eeea017 (Mono JIT Code) (wrapper managed-to-native) UnityEditor.EditorApplication:ExecuteMenuItem (string)
0x0000018d7eee9f73 (Mono JIT Code) UnityEditor.ShortcutManagement.MenuItemEntryDiscoveryInfo:<.ctor>b__7_0 (UnityEditor.ShortcutManagement.ShortcutArguments)
0x0000018d7eee7ec1 (Mono JIT Code) UnityEditor.ShortcutManagement.Trigger:HandleKeyEvent (UnityEngine.Event,UnityEditor.ShortcutManagement.IContextManager)
0x0000018d7eee72f3 (Mono JIT Code) UnityEditor.ShortcutManagement.ShortcutController:HandleKeyEvent (UnityEngine.Event)
0x0000018d7eee721b (Mono JIT Code) UnityEditor.ShortcutManagement.ShortcutIntegration:EventHandler ()
0x0000018d7eee712c (Mono JIT Code) UnityEditor.EditorApplication:Internal_CallGlobalEventHandler ()
0x0000018d4f4aaffd (Mono JIT Code) (wrapper runtime-invoke) object:runtime_invoke_void (object,intptr,intptr,intptr)
0x00007ffef9fde660 (mono-2.0-bdwgc) [mini-runtime.c:2812] mono_jit_runtime_invoke
0x00007ffef9f62af2 (mono-2.0-bdwgc) [object.c:2921] do_runtime_invoke
0x00007ffef9f6bb4f (mono-2.0-bdwgc) [object.c:2968] mono_runtime_invoke
0x00007ff75d238de4 (Unity) scripting_method_invoke
0x00007ff75d234451 (Unity) ScriptingInvocation::Invoke
0x00007ff75d22e6d5 (Unity) ScriptingInvocation::Invoke<void>
0x00007ff75c56c21b (Unity) Scripting::UnityEditor::EditorApplicationProxy::Internal_CallGlobalEventHandler
0x00007ff75d609c5a (Unity) CallGlobalInputEvent
0x00007ff75db1719e (Unity) GUIView::ProcessEventMessages
0x00007ff75db1122d (Unity) GUIView::GUIViewWndProc
0x00007fff64d6e7e8 (USER32) CallWindowProcW
0x00007fff64d6e229 (USER32) DispatchMessageW
0x00007ff75daf0406 (Unity) MainMessageLoop
0x00007ff75daf4186 (Unity) WinMain
0x00007ff75f654672 (Unity) __scrt_common_main_seh
0x00007fff650a7034 (KERNEL32) BaseThreadInitThunk
0x00007fff65ee2651 (ntdll) RtlUserThreadStart

I noticed I am not even calling the Execute method when I copied and pasted this. But I have the same result when I call Execute() in Start() in RoadGenerator. But why would only adding the import for UnityEditor and adding the AssetProcessor class at the bottom break the build?