Unable to start program. [VALUE].dll is not a valid Win32 application error in Visual Studio 2017

Question

I have developed an C#, ASP.NET web application in a Windows 7 machine using Visual Studio 2012. Now i had imported the entire project into VS 2017 running on windows 10 machine, and when i try to enter the debugging mode to analyze my code it shows the following error:

I guess the project configurations are conflicting hence it throws this error. Any suggestions??

Solution 1

The same error happens when Visual Studio solution has selected the wrong Startup Project. The bold project is the designated startup project.

Go to the Solution Explorer > Right click on the correct project and select "Set as StartUp Project" in the context menu.

Solution 2

I also got this error. I ultimately got to know that I was not selecting .sln file.

In VS, you should select .sln file and it automatically loads the complete project structrue is what I learnt.

Selecting .sln file worked for me

Solution 3

These errors are mostly because you are not selecting the .sln or solution file. In your solution explorer tree, double click the solution file and then build and run.

This runs contrary to a users intuition that simply opening a file and running it would work. Consider it a poor user interface. Jet Brains Rider, for instance, does not have this issue.

Comments

[CodingYoshi]

Try setting up your web project as the start-up project and then retry.

[user6304166]

@CodingYoshi sorry but i am new to VS could you please elaborate? How can i do that?

[CodingYoshi]

Right click the web project and on of the options should be set as startup or something similar.

[Matthias]

I experienced this issue once, randomly. I fixed it by restarting Visual Studio and installing the available package updates. (There will be a highlighted flag in the upper right if you have updates available.) This user also has a solution to a similar or the same problem, but I can't personally vouch for it.

[Agilanbu]

Try to provide a short hint about your answer. so that it will reach very soon. link never help

[Mike]

also try to double-clicking the .sln file. If the .sln not visible, click the "show all Files" icon in solution explorer