Question

We write some winForms GUI application that uses the Invariant Culture. So in the beginning of the Main we have:

    [STAThread]
    static void Main()
    {
        CultureInfo culture = CultureInfo.InvariantCulture;
        System.Threading.Thread.CurrentThread.CurrentCulture = culture;
        ... 

The problem is that on some machines it works perfectly but on some machines on some configurations ( like Debug/AnyCPU fro x64 machines) it raises SequrityException

Request for the permission of type 'System.Security.Permissions.SecurityPermission, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.

So what is the problem with it? And why it happens only on some conditions?

Answer 1

Another post mentions security issues when using the invariant culture. Perhaps this is your issue?

Using the InvariantCulture Property

The InvariantCulture property represents neither a neutral nor a

specific culture. It represents a third type of culture that is
culture-insensitive. It is associated with the English language but
not with a country or region. Your applications can use this property
with almost any method in the System.Globalization namespace that
requires a culture. However, an application should use the invariant
culture only for processes that require culture-independent results,
such as formatting and parsing data that is persisted to a file. In
other cases, it produces results that might be linguistically
incorrect or culturally inappropriate.

Security Considerations If a security decision will be made based

on the result of a string comparison or case change, your application
should use an ordinal comparison that ignores case instead of using
InvariantCulture. The default implementations of methods such as
Compare()()() and ToUpper use the CurrentCulture property. Code that
performs culture-sensitive string operations can cause security
vulnerabilities if CurrentCulture is changed or if the culture on the
computer running the code differs from the culture used to test the
code. The behavior that you expect when writing a string operation
differs from the actual behavior of your code on the executing
computer. In contrast, an ordinal comparison depends solely on the
binary value of the compared characters.

String Operations If your application needs to perform a

culture-sensitive string operation that is not affected by the value
of CurrentCulture, it should use a method that accepts a CultureInfo
parameter. The application should specify the value of the
InvariantCulture property for this parameter. The application should
use the property with methods such as Compare()()() and ToUpper to
eliminate cultural variations and ensure consistent results. For more
information about using the InvariantCulture property to perform
culture-insensitive string operations, see Culture-Insensitive String
Operations.

Persisting Data The InvariantCulture property is useful for

storing data that will not be displayed directly to users. Storing
data in a culture-independent format guarantees a known format that
does not change. When users from different cultures access the data,
it can be formatted appropriately based on specific user. For example,
if your application stores DateTime types in a text file, formatted
for the invariant culture, the application should use the
InvariantCulture property when calling ToString to store the strings
and the Parse method to retrieve the strings. This technique ensures
that the underlying values of the DateTime types do not change when
the data is read or written by users from different cultures.