无法在 Unity3d 中向对象添加新脚本

Question

I tried to add a script to a GameObject in the Hierarchy View in Unity. I dragged it before to my Scripts-Folder. I got the following message:

Can't add script behaviour AssemblyInfo.cs. The script needs to derive from MonoBahaviour!

I tested it with a new standard script - (Maybe copy and paste would bypass the problem) but also the new standard script gives me the message:

No MonoBehaviour scripts in the file, or their names do not match the filename.

I looked it already up and the following solutions don't apply to this case.

• The Script name is named exactly like the Monobehaviour Class
• Script Class inherits from the Monobehaviour Class
• There are no typos. (Class name doesn't contain spaces)
• I closed and reopend Unity
• Reset doesn't appear to work

You can check both scripts (which are basically the same) below:

I use Windows 10 Version 1909 and Unity 2018.4.10f as well a Coding on Visual Studio Code.

Maybe you know what's going on. Thanks

[Edit] There have been some error messages in the Console.

Generating diff of this object for undo because the type tree changed.This happens if you have used Undo.RecordObject when changing the script property. Please use Undo.RegisterCompleteObjectUndo

OnGUIDepth changed: was 0 is 3. Event type was 0

Answer 1

It is not a very good answer because I can't deliberately reproduce the answer as well I can't reproduce the problem. But now I again can add scripts to GameObjects in the Hierarchy View.

As in the following Link of a Unity tutorial about: Unity Project Folder Structure there exist the Visual Studio Solution File : .sln which contains information of the project enviroment and project state. Futhermore there is the Visual Studio C# Project File : .csproj as which contains project settings and references to files used by the project.

Infos are from https://fileinfo.com/extension/sln and https://fileinfo.com/extension/csproj

I deleted them. (Don't worry Unity autogenerates them.)

Nevertheless there was no immediate improvement. I deleted all script files and tried to drag and drop a new script file. Upon this action Unity crashed. After restarting Unity scripts could be created which worked again - or should I say Unity worked again because there was never a problem with the scripts.

I know, it's a botched solution but if this problem occurs to you and you tried all the bullet points in the question, (a) deleting .sln and .csproj files, (b) restarting Unity and (c) importing/creating new scripts might work.