Error while trying to create settings file

[Aberro]

Error message text:

Instance of ToolboxEditorSettings couldn't be created because there is no script with that name.
UnityEngine.ScriptableObject:CreateInstance (string)
Toolbox.Editor.ToolboxManager/<>c__DisplayClass9_0:<SettingsProvider>b__1 (string) (at ./Library/PackageCache/com.browar.editor-toolbox@bbffd34d1b/Editor/ToolboxManager.cs:175)
UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&)

followed by another error:

ArgumentNullException: Value cannot be null.
Parameter name: asset
UnityEngine.Object+MarshalledUnityObject.ThrowException[TException] (System.String message) (at <b0496629ff614f3f8bd13ba4916984de>:0)
UnityEngine.Object+MarshalledUnityObject.MarshalNullCheck[TException] (UnityEngine.Object obj, System.String parameterName) (at <b0496629ff614f3f8bd13ba4916984de>:0)
UnityEditor.AssetDatabase.CreateAsset (UnityEngine.Object asset, System.String path) (at <335b34ef534e437c860b1c21cb87dc9c>:0)
Toolbox.Editor.ToolboxManager+<>c__DisplayClass9_0.<SettingsProvider>b__1 (System.String searchContext) (at ./Library/PackageCache/com.browar.editor-toolbox@bbffd34d1b/Editor/ToolboxManager.cs:187)
UnityEditor.SettingsProvider.OnGUI (System.String searchContext) (at <335b34ef534e437c860b1c21cb87dc9c>:0)
UnityEditor.SettingsWindow.DrawControls () (at <335b34ef534e437c860b1c21cb87dc9c>:0)
UnityEditor.SettingsWindow.DrawSettingsPanel () (at <335b34ef534e437c860b1c21cb87dc9c>:0)
UnityEngine.UIElements.IMGUIContainer.DoOnGUI (UnityEngine.Event evt, UnityEngine.Matrix4x4 parentTransform, UnityEngine.Rect clippingRect, System.Boolean isComputingLayout, UnityEngine.Rect layoutSize, System.Action onGUIHandler, System.Boolean canAffectFocus) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e, UnityEngine.Matrix4x4 worldTransform, UnityEngine.Rect clippingRect, System.Action onGUIHandler, System.Boolean canAffectFocus) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e, System.Action onGUIHandler, System.Boolean canAffectFocus) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e, System.Boolean canAffectFocus) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.IMGUIContainer.SendEventToIMGUIRaw (UnityEngine.UIElements.EventBase evt, System.Boolean canAffectFocus, System.Boolean verifyBounds) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.IMGUIContainer.SendEventToIMGUI (UnityEngine.UIElements.EventBase evt, System.Boolean canAffectFocus, System.Boolean verifyBounds) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.IMGUIContainer.ProcessEvent (UnityEngine.UIElements.EventBase evt) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.IMGUIContainer.ExecuteDefaultActionAtTarget (UnityEngine.UIElements.EventBase evt) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.CallbackEventHandler.ExecuteDefaultActionAtTargetInternal (UnityEngine.UIElements.EventBase evt) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.EventDispatchUtilities.HandleEvent_DefaultActionAtTarget (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.BaseVisualElementPanel panel, UnityEngine.UIElements.VisualElement target) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.EventDispatchUtilities.HandleEventAtTargetPhase (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.BaseVisualElementPanel panel, UnityEngine.UIElements.VisualElement target) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.EventDispatchUtilities.DispatchToCapturingElement (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.BaseVisualElementPanel panel, System.Int32 pointerId, UnityEngine.Vector2 position) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.EventDispatchUtilities.DispatchToCapturingElementOrElementUnderPointer (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.BaseVisualElementPanel panel, System.Int32 pointerId, UnityEngine.Vector2 position) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.MouseEventBase`1[T].Dispatch (UnityEngine.UIElements.BaseVisualElementPanel panel) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.EventDispatcher.ProcessEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.BaseVisualElementPanel panel) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.EventDispatcher.ProcessEventQueue () (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.EventDispatcher.OpenGate () (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.EventDispatcherGate.Dispose () (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.EventDispatcher.ProcessEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.BaseVisualElementPanel panel) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.EventDispatcher.Dispatch (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.BaseVisualElementPanel panel, UnityEngine.UIElements.DispatchMode dispatchMode) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.BaseVisualElementPanel.SendEvent (UnityEngine.UIElements.EventBase e, UnityEngine.UIElements.DispatchMode dispatchMode) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.UIElementsUtility.DoDispatch (UnityEngine.UIElements.BaseVisualElementPanel panel) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.UIElementsUtility.UnityEngine.UIElements.IUIElementsUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& eventHandled) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.UIEventRegistration.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.UIElements.UIEventRegistration+<>c.<.cctor>b__1_2 (System.Int32 i, System.IntPtr ptr) (at <bbc67888babf4b1bb902e41b96b884a0>:0)
UnityEngine.GUIUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& result) (at <5c4beea130f443f7af2be835cb11f79f>:0)

[arimger]

Can you create ToolboxEditorSettings through Create Asset Menu or does this error still appears?

Project Window -> RMB -> Create -> Toolbox -> Settigns

I suggest reloading the whole package because this looks very strange. If you are using UPM, you can remove and re-add the package.

[Aberro]

Yes, I can create it. But I still getting warning message "[Editor Toolbox] Settings initialization needed. Go to Edit/Project Settings.../Editor Toolbox and find an existing Settings file ('Refresh') or create new."

I've tried re-adding the package, but the problem still persists.

[Aberro]

Hm, also, after restarting Unity editor, this settings seems to be of an unknown script, i.e. this:

[Aberro]

I've fixed it, after another re-install, reimporting all assets and re-creating settings file though context menu (haven't tried it in project settings).