We Keep Coding

error CS0246: The type or namespace name 'BannerPosition' could not be found are you missing a using directive or an assembly reference?

Assets\Scripts\BannerAd.cs(7,22): error CS0246: The type or namespace name 'BannerPosition' could not be found (are you missing a using directive or an assembly reference?)
using UnityEngine;
using System.Collections;
using UnityEngine.Advertisements;
[SerializeField] BannerPosition _bannerPosition;
nothing i copied this cod from video

BannerPosition should be declared as a Class (a script), maybe you missed it in the video or you didn't reach when it's going to be created.

The UnityEngine.Advertisements asmdef doesn't compile because you probably don't fulfil the define constraints.
https://forum.unity.com/threads/how-should-i-install-unity-ads-in-my-game-asset-store-package-package-manager-or-services-window.699005/
Look at this thread and start your package installation over.

Missing assembly reference to implement an `IPreprocessBuildWithReport`?

All I want is to implement a simple IPreprocessBuildWithReport to write a .csv file...
using System.IO;
using System.Text;
using UnityEditor;
using UnityEditor.Build;
using UnityEditor.Build.Reporting;
using UnityEditor.Callbacks;
namespace My.App.Scripts
{
public class MyStuffDoer : IPreprocessBuildWithReport
public int callbackOrder => 0;
public void OnPreprocessBuild(BuildReport report)
{
DoMyStuff();
}
[DidReloadScripts]
public static void DoMyStuff()
{
...
}
}
}
Rider is happy to accommodate me, but Unity is refusing to build, insisting that
The type or namespace 'Build' does not exist in the namespace 'UnityEditor' (are you missing an assembly reference?)
The type or namespace 'Callbacks' does not exist in the namespace 'UnityEditor' (are you missing an assembly reference?)
The type or namespace 'IPreprocessBuildWithReport' could not be found (are you missing a using directive or an assembly reference?)
The type or namespace 'BuildReport' could not be found (are you missing a using directive or an assembly reference?)
The type or namespace 'DidReloadScriptsAttribute' could not be found (are you missing a using directive or an assembly reference?)
The type or namespace 'DidReloadScripts' could not be found (are you missing a using directive or an assembly reference?)
Stop asking me, Unity, I don't know! AM I?!
Can't seem to find anything remotely useful on the internet in regards to this.
And all the examples I find just toss their IPreprocessBuildWithReport implementation at me, with absolutely no mention of an assembly.
How do you implement an IPreprocessBuildWithReport?

You need to put your editor scripts into folders called "Editor" = )
Your script compiles and runs in the editor environment. Your specific method is found and executed by the editor when building the executable app. But since it's an Editor script, and not a production script, it needs to be recognized by Unity as being part of the extended Editor, not of your app.
Unity is not always intuitive, but it does love you <3

Autocount project won't build

I'm working on an autocount project that should deploy in autocount 1.8 but when I try to build it I get the following errors:
The type or namespace name 'LicenseStatusArgs' could not be found (are you missing a using directive or an assembly reference?) in plugininit.cs
The type or namespace name 'AccountantColumnChangedEventArgs' does not exist in the namespace 'BCE.AutoCount.Option' (are you missing an assembly reference?) in options.cs
The type name 'FormShownEventArgs' does not exist in the type 'BCE.AutoCount.MainEntry.FormMain' in option.cs and mainformscript.cs
Is this because of a licensing issue? I apologize if this isn't the right place to put this kind of question.

How can I determine which assemblies or using declarations need to be added for WPF classes?

I'm trying to use an IsolatedStorageFileStream based Simon McKenzie's comment here, but adding this code:
IsolatedStorageFileStream isfs = null;
...gives me, "The type or namespace name 'IsolatedStorageFileStream' could not be found (are you missing a using directive or an assembly reference?)"
I reckon I am (missing a using directive or an assembly reference), but what, exactly? Right-clicking IsolatedStorageFileStream does not give me a "Resolve" option, and adding:
using System.IO.IsolatedStorage;
...gives me, "The type or namespace name 'IsolatedStorage' does not exist in the namespace 'System.IO' (are you missing an assembly reference?)"
Googling for "example of using IsolatedStorageFileStream in wpf" hasn't helped, either.
How can I find out which assembly is needed, or which using is needed?

type or namespace name '...' could not be found (are you missing a using directive or an assembly reference?)

This work's fine for another app that I'm transferring into this one. I've been stuck here for hours and google does not have much for MEF. the System.ComponentModel.Composition.dll is imported, yes. But still cannot get rid of this error.
I have this for my includes:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using System.ComponentModel.Composition;
using JSNet;
Affected code:
var catalog = new AggregatingComposablePartCatalog();
var mainAssemblyCatalog = new AttributedAssemblyPartCatalog(this.GetType().Assembly);
var jsNetCatalog = new AttributedAssemblyPartCatalog(typeof(Effect).Assembly);
//var addInEffects = new DirectoryPartCatalog("Effects");
catalog.Catalogs.Add(mainAssemblyCatalog);
catalog.Catalogs.Add(jsNetCatalog);
//catalog.Catalogs.Add(addInEffects);
var container = new CompositionContainer(catalog);
Errors:
Error 1: The type or namespace name 'AggregatingComposablePartCatalog' could not be found (are you missing a using directive or an assembly reference?)
Error 2: The type or namespace name 'AttributedAssemblyPartCatalog' could not be found (are you missing a using directive or an assembly reference?)
Error 3: The type or namespace name 'AttributedAssemblyPartCatalog' could not be found (are you missing a using directive or an assembly reference?)
Error 4: The type or namespace name 'CompositionContainer' could not be found (are you missing a using directive or an assembly reference?)

Check if your app's framework version is set to Client Profile. If it is, this is your problem. The assembly you're referencing likely isn't targeting Client Profile. Change it to .NET 4.0 (not 4.0 Client Profile)