Why is my project's assembly missing from the package when I debug?

Question

I've got a SharePoint project that I've been debugging for some time without problems.

Today I added a feature receiver to the project's only feature. I've not yet changed anything about the empty receiver class that Visual Studio adds by default.

The "Package" command now generates a package which includes my project's DLL file (as you'd expect -- adding a feature receiver shouldn't change anything about this).

However, when I debug, the generated package does not include my project's DLL file, and the deployment effort fails with the following error:

Error occurred in deployment step 'Add Solution': Failed to load receiver assembly "ABC, Version=1.0.0.0, Culture=neutral, PublicKeyToken=2377fad544a7c307" for feature "ABC_XYZ Feature" (ID: dca34989-a2f2-413b-b5c4-958e0bbb84ef).: System.IO.FileNotFoundException: Could not load file or assembly 'ABC, Version=1.0.0.0, Culture=neutral, PublicKeyToken=2377fad544a7c307' or one of its dependencies. The system cannot find the file specified. File name: 'ABC, Version=1.0.0.0, Culture=neutral, PublicKeyToken=2377fad544a7c307' at System.Reflection.Assembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection) at System.Reflection.Assembly.InternalLoad(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) at System.Reflection.Assembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) at System.Reflection.Assembly.Load(String assemblyString) at Microsoft.SharePoint.Administration.SPFeatureDefinition.get_ReceiverObject()

WRN: Assembly binding logging is turned OFF. To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1. Note: There is some performance penalty associated with assembly bind failure logging. To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].

Removing the feature receiver allows me to again debug without issue, but the problem returns as soon as I re-add the feature receiver.

I've tried cleaning and rebuilding, and then debugging, but the error won't go away unless/until I remove the feature receiver.

Why does my project's assembly get included in the package when I use the "Package" command, but not when I use the "Start Debugging" command, and what about adding the feature receiver causes this to happen?

Answer 1

The accepted answer to this question did not work for me.

The following did work:

...simply changing out the project’s strong key assembly worked in this particular case. If you haven’t had to change this before, it is under the properties of the project -> Signing. Under ‘Choose a strong name key file’, select New. The password is optional.

Thanks to this blog post: Farm Solution Deployment Problems