KB: Attempt by security transparent method X to access security critical method Y failed

This runtime error will occur when a function is called that has code utilising another function or class that has not specified it's security level.

To resolve this, you can add "[SecuritySafeCritical]" above the calling function, like this:

using System.Security;

[SecuritySafeCritical]
void the_callee()
{
    the_problematic_function();
}

void the_problematic_function()
{
    ...
}