System.BadImageFormatException: Could not load file or assembly

Question

C:\Windows\Microsoft.NET\Framework64\v4.0.30319>InstallUtil.exe C:\_PRODUKCIJA\D
ebug\DynamicHtmlTool.exe
Microsoft (R) .NET Framework Installation utility Version 4.0.30319.1
Copyright (c) Microsoft Corporation.  All rights reserved.

Exception occurred while initializing the installation:
System.BadImageFormatException: Could not load file or assembly 'file:///C:\_PRO
DUKCIJA\Debug\DynamicHtmlTool.exe' or one of its dependencies. An attempt was ma
de to load a program with an incorrect format..

C:\Windows\Microsoft.NET\Framework64\v4.0.30319>

service is x86 compiled even both computers are x64 and it works on my computer. Here in server where is win 2008 i get this error.

i try solutions from google but none works.

Like write here i have x86 project http://www.davesquared.net/2008/12/systembadimageformatexception-on-64-bit.html

I did a clean build then a build and the error went away – PUG May 26 '15 at 20:30 — PUG, May 26 '15 at 20:30

score 303 · Accepted Answer · edited Jan 23 '17 at 06:51

303

It seems that you are using the 64-bit version of the tool to install a 32-bit/x86 architecture application. Look for the 32-bit version of the tool here:

C:\Windows\Microsoft.NET\Framework\v4.0.30319

and it should install your 32-bit application just fine.

edited Jan 23 '17 at 06:51

Sizons

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answered Mar 08 '11 at 07:04

madd0

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or change in Visual Studio(compiler settings) the target from “X86 ” to “Any CPU”. – Tim Schmelter Oct 25 '12 at 15:07
@TimSchmelter I wish I would have seen it here first. That is what I did and it worked (changed the target from Any CPU in my case to match my referenced project - x64). – FernandoZ Aug 25 '20 at 16:42
For me, I had selected x86 for my debug target... twice (I blame my dyslexia) – Peter L Apr 21 '21 at 15:52
Note: Ran into the same error with .Net Framework libraries referenced from .Net Standard when the CPU targets were not set to be the same. So this error still very much exists in recent .Net releases. – Jeff Jul 17 '23 at 20:48

score 155 · Answer 2 · edited Mar 08 '11 at 07:11

155

Try to configure the setting of your projects, it is usually due to x86/x64 architecture problems:

Go and set your choice as shown:

edited Mar 08 '11 at 07:11

Cody Gray - on strike

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answered Mar 08 '11 at 07:07

David

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This was it for me as well. – Bill Sambrone Feb 14 '13 at 23:48
Just ran into this problem, and this fixed it. Thanks! – Alexander Forbes-Reed Mar 11 '13 at 16:45
1

@David How did you get "Mixed Platforms" in you dropdown. I have VS2013 and my only options are "Any CPU", "x64" and "x86". – Ottak Nov 12 '14 at 18:32
@Ottak I believe you can [create your own?](https://msdn.microsoft.com/en-us/library/kwybya3w.aspx) (I might have the wrong article referenced) – Jesus is Lord Dec 05 '17 at 18:34
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**Test>Test Settings> Default Processor Architecture > x64** worked for me. – learntogrow-growtolearn May 01 '18 at 18:28

score 129 · Answer 3 · edited May 09 '18 at 15:09

129

I found a different solution to this issue. Apparently my IIS 7 did not have 32bit mode enabled in my Application Pool by default.

To enable 32bit mode, open IIS and select your Application Pool. Mine was named "ASP.NET v4.0".
Right click, go to "Advanced Settings" and change the section named: "Enabled 32-bit Applications" to true.

Restart your web server and try again.

I found the fix from this blog reference: http://darrell.mozingo.net/2009/01/17/running-iis-7-in-32-bit-mode/

Additionally, you can change the settings on Visual Studio. In my case, I went to Tools > Options > Projects and Solutions > Web Projects and checked Use the 64 bit version of IIS Express for web sites and projects - This was on VS Pro 2015. Nothing else fixed it but this.

edited May 09 '18 at 15:09

Gabriel Tapizquent

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answered Apr 01 '12 at 01:07

Joseph Snow

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Thank you, this reminded me of how to fix a similar problem! – Steven Quick Mar 22 '13 at 02:45
Can you stick this on http://stackoverflow.com/questions/323140/system-badimageformatexception-incorrect-format-when-trying-to-install-service?lq=1 (but qualify it ery clearly by saying that it is not an installutil case, just the same exception) – Ruben Bartelink May 15 '13 at 20:48
It was my case, thanks a lot. – Aycan Yaşıt Jul 20 '16 at 19:36
This was super helpful to me. Sometimes VS/IIS error messages are less than useful. – Musical Coder Oct 29 '18 at 20:56
@Joseph It is not enabled, It is blurred – k_kumar May 17 '19 at 13:15
This solved my issue – marifrahman Aug 19 '20 at 11:46
Thank you so much for this post. Enable 32-bit solved my issue. – AdamB Nov 24 '20 at 11:54

score 6 · Answer 4 · answered Apr 12 '13 at 08:08

6

I had the same exception installing using correct framework.

My solution was running cmd as administrator .... then it worked fine.

answered Apr 12 '13 at 08:08

woony

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Strange, if you have more detail or a rationale, no harm to stick it on http://stackoverflow.com/questions/323140/system-badimageformatexception-incorrect-format-when-trying-to-install-service?lq=1 (But I'd downvote it unless there is a rationale as this doesnt make sense to me :P) – Ruben Bartelink May 15 '13 at 20:49
I never stated I could explain why, because I can not. My dots .... might have indicated the fact , that it didn't make any sense for me aswell. But from experience that is not uncommon using anything microsoft. – woony May 17 '13 at 11:32
I normally find that stuff that doesn't make sense doesn't make sense for a reason and PEIMS is easier than PEBKAC. It is my contention that you did more than just this single thing different as this makes no sense. The error is a 64/32 bit conflict and running as Admin can't influence that without some mad path redirections or profiles confusing matters. But it's highly unlikely so I dont think this is a helpful answer for anyone so -1 – Ruben Bartelink May 17 '13 at 11:56
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@RubenBartelink, if Woony had a workaround, that helped him, it's good to share, even if he can't explain why. It's not a reason to down-vote, in particular when there are other high-voted answers – Michael Freidgeim May 20 '13 at 20:05
@MichaelFreidgeim And if he ran around his house/apartment block three times and then rebooted and that fixed it? Would *you* upvote the answer if it had 0 votes instead of -1 ? It doesn't really make sense when you think about it. – Ruben Bartelink May 20 '13 at 20:13
1

I've upvoted only to compensate your downvote. Be nice to new users. Btw, reboot often helps, but I never tried to run more than twice around the apartment block :). – Michael Freidgeim May 20 '13 at 20:21
:) I've had this same debate with others before (normally on the 'relax with the rules' stance). I know it's nice to be nice but we'll have to agree to disagree on the 'try this thing I can't explain'. And coincidentally today, I asked for a reopen http://stackoverflow.com/questions/16644146/eventstore-commit-guid-what-is-it-really-used-for (new user, but key thing:- a good question) but had another such 'debate':- http://stackoverflow.com/questions/329355/cannot-delete-directory-with-directory-deletepath-true/14933880#comment23947114_7518831 - Do you agree with that one too :P – Ruben Bartelink May 20 '13 at 21:16
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This is a tad old.... But in Woony's defense..... 9 months later, and this is what solved my issue. – Johnrad Jan 15 '14 at 19:31

score 3 · Answer 5 · edited Feb 06 '14 at 12:49

3

My cause was different I referenced a web service then I got this message.

Then I changed my target .Net Framework 4.0 to .Net Framework 2.0 and re-refer my webservice. After a few changes problem solved. There is no error worked fine.

hope this helps!

edited Feb 06 '14 at 12:49

Lucky

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answered Jan 04 '12 at 13:40

Davut Gürbüz

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What are **a few** changes? – Michael Freidgeim May 20 '13 at 19:57
@MichaelFreidgeim it was an old issue for me. But as far as I remember when I changed my framework generated proxy changed so I did some re-factoring.This was my intention for "a few changes". – Davut Gürbüz May 21 '13 at 00:33

System.BadImageFormatException: Could not load file or assembly

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