Question: I'm not sure if anyone else has encountered this but often, when I open this particular solution, I see a whole list of errors (see below). 

[![Error Image](https://i.stack.imgur.com/DWV60.png)](https://i.stack.imgur.com/DWV60.png)

If I double click one of them, then Visual Studio seems to wake up and the errors relating to that particular `cs` file disappear. This isn't a critical issue and is more on an irritation than anything else but I wonder, is there perhaps something wrong with my code that's causing this false-positive or is it random Visual Studio behaviour?

Answer: 
I had this problem too. 
Deleting bin and obj folders not work. 
Cleaning solution not work. 
Various platform I need to be as is. 

Helped me close solution and delete folder .vs, which is often full of problematic mess. After opening solution all false errors disappeared.
Something that has only become evident in later years, and is only relevant upon reflection on this old question, is that the particular solution that we experience this issue in contains a Website project and NOT a WebApplication project. This became evident when we started to look deeper into these recurring errors and noted that they only ever related to codebehind files and all had to do with the `Control` Name not existing in the current context.

Amongst the various differences between the two project types, it seems that the lack of designer files for each ASP page may be a contributing factor. The error disappears as soon as you double click it potentially indicating that VS is not able to keep track of the control references until you open the relevant page / codebehind file.

We're moving over to a Web Application as a temporary measure.

Hope this insight helps someone else!