[c#] Name does not exist in the current context

I also faced a similar issue, the problem was the form was inside a folder and the file .aspx.designer.cs I had the namespace referencing specifically to that directory; which caused the error to appear in several components:

El nombre no existe en el contexto actual

This in your case, a possible solution is to leave the namespace line of the Members_Jobs.aspx.designer.cs file specified globally, ie change this

namespace stman.Members {

For this

namespace stman {

It's what helped me solve the problem.

I hope to be helpful