为什么我会得到“组装”*。dll必须具有强大的签名才能被标记为先决条件。

I'm trying to compile my excel addin using C# 4.0, and started to get this problem when building my project in Visual Studio. It's important to tell you that I haven't had this problem before. What could cause this to happen?I'm trying to compile my excel addin using C# 4