TypeInitializationException thrown for Program class

Question

My Windows Forms application was working earlier, however suddenly it stopped working. I am getting following exception:

With exception details as follows:

System.TypeInitializationException was unhandled
Message: An unhandled exception of type 'System.TypeInitializationException' occurred in mscorlib.dll
Additional information: The type initializer for 'NotificationTester.Program' threw an exception.

When I click OK, the VS windows then shows following:

The solution was working fine earlier. I don't get whats going wrong.

Answer 1

So: either one of the field-initializers, or the static constructor, for Program - is failing. Find out why. Note: the InnerException has the actual exception that was raised, but basicaly: just debug the field initializers and static constructor. So look inside the Program class for either:

static SomeType someField = /* some non-trivial expression or method call */ 

or:

static Program() {
    // stuff
}

Answer 2

Another possible reason: the app.config has duplicate sections.

Answer 3

A possible reason: init a static dictionary with duplicated keys.

Answer 4

I got the same error message and for my case the reason is my main program is set to build as 32 bit console app and I added a private variable logger which access a 64bit dll.

public class Program
{
    public static readonly Logger logger = new Logger(typeof(Program));

After I changed the main program to be build as 64bit, the issue is fixed.

Answer 5

In my case the reason was, that <configSections> wasn't first one in config file.

Only one <configSections> element allowed per config file and if present must be the first child of the root <configuration> element.

Move the configSections element to the top in your config file.

Hope it helps to someone.

Answer 6

I've got the same error with platform target set as any CPU and prefer 32-bit checked, unchecking that last one solved my problem.

Answer 7

This is one weird issue I had to deal with for the last 2 hours. I solved it by removing the static from the lists I created.

private static readonly List<Person> someList = GlobalConfiguration.Connection.PopulateList();

with this one:

private readonly List<Person> someList = GlobalConfiguration.Connection.PopulateList();

Hope it helps and you don't have to spend two hours to find out the bug...

Answer 8

Make sure you are not missing any dependency DLLs. In my case, a DLL I was referencing had a dependency on another DLL.

If this is what happened, look at the "Inner Exception" property and then you will see a better error message. In my case, it said "Cannot find xxx.dll"

Answer 9

So, If you didn't get an innerException message like me, you can set a breakpoint on some of the static variables like strings that you may have declared. Then you can debug forwards from there with F10.

Answer 10

In my case it was a very silly thing. I had accidentally typed something like this

<configuration>
    <appSettings>
         <add key="someKey" value="SomeValue" />sss
         <add key="someKey1" value="SomeValue1" />
    </appSettings>
</configuration> 

sss - Caused the error for me. Any random character entry.

Answer 11

This issue for me was caused by a rogue user.config file that was created in the AppData\Local[Manufacturer][Product Name] directory. I'm not sure how it got there, but seems to be created every now and then.

Answer 12

After trying all of the answers listed here, I have a new one:

The type initializer for 'MyLibrary' threw an exception.

If you see something like the below in the InnerException(s)..........

"Could not load file or assembly 'log4net, Version=1.2.13.0, Culture=neutral, PublicKeyToken=669e0ddf0bb1aa2a' or one of its dependencies. The system cannot find the file specified.":"log4net, Version=1.2.13.0, Culture=neutral, PublicKeyToken=669e0ddf0bb1aa2a"

In my case, my directory had the correct version dll. (log4net.dll in this case).

And then ... the issue was found. Assembly redirects in the app.config.

:(

Since I had the correct version, I removed all my redirects. Your situation may be different.

  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="log4net" publicKeyToken="b32731d11ce58905" />
        <codeBase version="1.2.9.0" href="log4netv1.2.9.0\log4net.dll" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="log4net" publicKeyToken="1b44e1d426115821" />
        <codeBase version="1.2.10.0" href="log4netv1.2.10.0\log4net.dll" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="log4net" publicKeyToken="669e0ddf0bb1aa2a" />
        <codeBase version="1.2.13.0" href="log4netv1.2.13.0\log4net.dll" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>

Answer 13

I've the same problem: runs program in MS VS 2015 and triggers an exception message:

System.TypeInitializationException was unhandled
Message: An unhandled exception of type 'System.TypeInitializationException' occurred in mscorlib.dll
Additional information: Der Typeninitialisierer für "<Module>" hat eine Ausnahme verursacht.

The question where source this exception? So, I started the EXE file and displayed the exception message dialog. Answer on "debug mode" with MS VS so become more information displayed about exception.

System.IO.FileNotFoundException was unhandled
    Message: An unhandled exception of type 'System.IO.FileNotFoundException' occurred in mscorlib.dll
    Additional information: Die Datei oder Assembly "SIC, Version=19.2.6.3, Culture=neutral, PublicKeyToken=**************" oder eine Abhängigkeit davon wurde nicht gefunden. Das System kann die angegebene Datei nicht finden.

I go to this reference and analyse properties Property: "Copy Local" is on false - because before was a installed into GAC Solution: property "Copy Local" set on true and builds new assembly and works :-)

Maybe this information helpful! So have a good day.