“mscorlib.pdb not loaded” yet the mscorlib.dll is NOT missing

Question

I am running my application in VS2012 and I am getting a runtime error;

When I

Answer 1

This can happen when you initialize a variable in your class declarations and that initialization throws an exception:

class Program
{
    static OracleConnection ora = getOracleConnection(); 

}
static void main(string[] args) 
{
    ora.Open();
}
static OracleConnection getOracleConnection()
{
   OracleConnection orax = new OracleConnection(description=(host=myHost)
    (port=1521)(protocol=tcp))(connect_data=(sid=mySid)));user id=user;password=pw;
}

If an exception is thrown by getOracleConnection() you can get this error. Move your assignment (but not necessarily your declaration) inside of main (where it belongs anyway), and you will get the actual exception that is causing the error instead of the mscorlib error.

Answer 2

Goto Tools, Options, Debugging, General, Enable Just My Code

This will prevent the debugger from trying to launch on a Internal .NET Framework Assembly.

Answer 3

This happened to me for a different reason: I had referenced an old version of NLog (2.0) and needed to reference version 4.0, instead.

Answer 4

In a VB console app, in my case it was none of the above.

Just doing a string calculation in the Dim declarations before my subs.

The offending code:

Dim FylPrefix$ = Fyl.Substring(0, Fyl.LastIndexOf("."))

Moving this calculation into the sub it was needed in fixed it! GERONIMO!!

Answer 5

I had this issue when I was using a static variable, whose value is assigned off a static method.

So, whenever I ran the application, this line of code threw exception. If you place a debug point on this (like I did), you will notice the exception being thrown.

Answer 6

The best Solution to solve this error is:

1: Open App.config file.

2: Paste this useLegacyV2RuntimeActivationPolicy="true" code in the startup tag.

3: Save it.

Now the error would disappear. Moreover see Image. I have done this for you.