Error: A strongly-named assembly is required

Yet another possible cause:

(for desperate troubleshooters)

In Solution Explorer window, if you walk down your references list and check each in Properties window, seeing property Strong Name = False points to potential problem.

What the error means

"Strong Name : Indicates that the reference has been signed with a key pair."

If your current project's assembly is signed, then all your reference assemblies must also be signed. Failure to do so will result in this error.

How to check

Solution Explorer > References > [Click on the reference in question] > Properties

How to fix

Method 1 : Unsign your current project's assembly.

Project Properties > Signing > Sign the assembly (checkbox)

Method 2 : Sign the assembly of the reference project. (If you're building it yourself)

I've removed the license file from My Project Folder, and re-build again, it was build successfully.

Check the references section of each project in the solutions explorer... Look for references to third party vendor assemblys Like Infragistics, or Data Dynamics, etc. that might not be installed on the machine where you are experiencing the issue

Ok, not sure if this will help, but if you have access to ildasm, examine the three third party assemblies and check the following:

(I found the following googling on your error msg) Its from another guys post, so ignore the names, but the key is that inside the manifest the line should read ".publickeytoken" not ".publickey" Link to this thread is at:

http://social.msdn.microsoft.com/Forums/en-US/clr/thread/56e13ab1-4c03-4571-92f1-759081bcc78b/

Public Key or Token: ab 1a 81 37 f9 79 0c 88 

Looks ok, right? That sequence really is the public key token of Reflex.dll.

The problem can be seen if we use the ildasm gui and click on "manifest":

.assembly extern Reflex
{
.publickey = (2F 5A 20 3A 86 D3 5F 71 ) // /Z :.._q
.ver 1:0:0:0
}

Notice the .publickey line.

It should say .publickeytoken!!!

The problem is that the Cecil module, when creating the modified assembly, puts the public key token in the public key field (or forgets to turn on some flag that says that thiss is a token, not a complete public key. I'm unaware of the details).

So this amounts to a probable bug in Cecil. I should have used Gael's thing instead. :)

Anyway, now I know that the ONLY problem with the original script (before I moved to Cecil) was that it was putting a reference to a non-strongly-named assembly (Reflex) inside a strongly-named assembly (FXCOP).

So I fixed that now and re-ran my original script and ... viola! It works!!

I had been using many third-party libraries (MS Ent Lib) and decided to move a few of the dll's to an 'unused' folder. This gave me the error in question. I believe one of the libraries I referenced actually references another library that needs to sit alongside it (even though the dll does not need to be referenced in your project).

After moving the libraries back everything compiled without this error.

It could be that you have to specify your target platform explicitly and set it to x86. There might be an issue with the 64bit build.

Another thing: Do you run VS as Administrator? There are issues with VS2005 when it is not running with elevation on Vista, maybe this strange compile error is one of them.

A strange fix for me, but I had just pulled this solution from source control.

Was getting this error, went through most of the answers above, and then deleted the solution and re-pulled the solution from source control.

Worked.

Will only apply to a few, but I guess I was one of the few so there will be more. Not sure what happened the first time, but somehow some assemblies must have had some issues when I pulled them across.

Essentially turn it off and on again.