Visual Studio Solution Unavailable (reload doesn't work)

Question

I am downloading a sample program for a barcode reader that I am using. Everytime I download the program and run it I am prompted with the error in my solution explorer (see image below).

Any suggestions? Everytime I right click and reload project, it reloads quickly and then reverts back to unavailable.

Suggestions?

EDIT: Here is the link to the project (scroll to the bottom, PC Sample Program)

http://www.barcodereader.com/download/connections.php

CS Project File Example

Microsoft Visual Studio Solution File, Format Version 11.00
# Visual Studio 2010
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SrEthernetSample",     
"SrEthernetSample\SrEthernetSample.csproj", "{7A2F3660-184B-4553-ADEF-3071D718A501}"
EndProject
Global
GlobalSection(SolutionConfigurationPlatforms) = preSolution
    Debug|Any CPU = Debug|Any CPU
    Release|Any CPU = Release|Any CPU
EndGlobalSection
GlobalSection(ProjectConfigurationPlatforms) = postSolution
    {7A2F3660-184B-4553-ADEF-3071D718A501}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
    {7A2F3660-184B-4553-ADEF-3071D718A501}.Debug|Any CPU.Build.0 = Debug|Any CPU
    {7A2F3660-184B-4553-ADEF-3071D718A501}.Release|Any CPU.ActiveCfg = Release|Any CPU
    {7A2F3660-184B-4553-ADEF-3071D718A501}.Release|Any CPU.Build.0 = Release|Any CPU
EndGlobalSection
GlobalSection(SolutionProperties) = preSolution
    HideSolutionNode = FALSE
EndGlobalSection
EndGlobal

Answer 1

I faced this problem recently. The procedure below worked for my solution:

1. Right click the project which is not loading, in VS Solution Explorer
2. Click on Remove and confirm the removing process
3. Right click the Solution and select Add > Existing Project
4. Browse to the .csproj file in the project folder

If the above procedure does not work, then check the .NET targeted framework. May be Framework Incompatibility must be also one reason of the problem

If it shows error while you perform above steps then please check this

You do not have permission to access the IIS configuration file - Web app error

Answer 2

I was having the same problem on VS 2017 CE. I opened a .sln and the solution was empty (unavailable).

This solved my problem:

1. open the .sln file in VS
2. right click on the project name (unavailable) in the solution explorer
3. click on "install missing..." (i don't remember the exact text)

Answer 3

Have you tried re-adding the project to the solution from within VS? That can fix an invalid path