error cs0103 The Name 'IEnumerator' does not exist in the current context

Question

I have problem in C# development in monodevelop tool for unity. In that many methods and Interfaces not found like IEnumerator and Array.Length .

I found Same question but it's not work for me. because solution of that question is import System.Collections namespace but I was already imported it then also throw compile time error. I Have installed latest .Net Framework on Windows 8.1 Os.

How i solve this problem?

Answer 1

I have had that problem before. I was using the latest .net framework and I went to Programs and Features within control panel (if you're using Windows) and selected the box to also run .net framework 3.5 I think it was.

I then shut down my project after saving, restarted my machine and it worked fine

Answer 2

Close the project from MonoDevelop by doing Right Click. And open the *.sln file manually in MonoDevelop

Answer 3

I'm using Debian and I had your error, this error , and both was fixed by installing these packages:

mono-reference-assemblies-2.0
mono-reference-assemblies-3.5

Using APT:

sudo apt install mono-reference-assemblies-2.0 mono-reference-assemblies-3.5