How do I resolve "%1 is not a valid Win32 application"?

Question

Environment:
Windows Server 2003 R2 Enterprise 64bit, SP2
.NET framework is supposedly installed (2.0 SP2, 3.0 SP2, 3.5 SP1)

I say "supposedly" because they are listed as installed under Add/Remove programs. I'm not sure it's properly installed, because the "ASP.NET" tab isn't added to any of the sites in IIS.

In the IIS Web Service Extensions section, I have both "ASP.NET v2.0.50727" (Allowed), and "ASP.NET v2.0.50727 (32-bit)" (Prohibited).

The site in question has script-execute enabled.

Problem:

I created a super-simple ASP.NET/C# website: Default.aspx with a label id="Label1", and a code-behind with: Label1.text = "Hello World"; and the error I'm getting is:

%1 is not a valid Win32 application.

Solution 1

Have you tried running:

aspnet_regiis -i

from the command line?

Solution 2

Also check your application pool. In a 64-bit environment, you may need to set "Enable 32-bit applications" in Advanced Settings.

Solution 3

I had "%1 is not a valid Win32 application." error message because my PATH environment variable was messed up as well. It included this garbage from a python install:

%PYTHON_HOME%;
%PYTHON_HOME%\Scripts;

Solution 4

I had "%1 is not a valid Win32 application." error message because my PATH environment variable was messed up. Well, more specifically, the PATH itself had nothing wrong with it. Instead, I had accidentally created a file named "C:\Program" that was used instead of "C:\Program Files\" for path lookup. The accidental creation of "C:\Program" was a result of calling Notepad++ on the command line for C:\Program Files\test.txt (without quotation marks), so Notepad++ thought I was trying to edit a file called "C:\Program" and created the file for me.

Solution 5

I had this problem. I deployed an .EXE to a Windows 2003 that doesn't support .NET 4.5. I rebuilt the program with .NET 4 and it worked.

View more solutions

Comments

[Adam Tuttle]

After some Googling, I found that I have 2 copies of this exe, one in Windows\...\Framework\ and one in ...\Framework64\. Running the one in Framework64 says IIS is in 32 bit mode & not compatible, so I used the other one. Executed successfully, but now I don't even get the same error, just a 404.

[Adam Tuttle]

After a server reboot, I finally got the standard .NET error page, which led me to figure out that the folder needed to be defined as its own application in IIS. After I did that, everything seems to be working. Thanks!

[Adam Tuttle]

But for what it's worth, I still don't have an ASP.NET tab for any sites in IIS.

[Steve Pitchers]

From the command line? Do you mean specifically the Visual Studio command prompt?

[Vadzim]

Here is the explanation: stackoverflow.com/questions/16455855/…