ClrObject static method invocation error calling external dll in AX2009

Hi all

I try to call a external dll (placed in the bin-directory where the AOS is located). The reference in AX is done.

My call looks like the followingprotected boolean createContractList()
{
    InteropPermission   interopPerm;
    Integer             ret;
    ;

    // get CLR interop permission
    interopPerm = new InteropPermission(InteropKind::ClrInterop);
    interopPerm.assert();

    ret = ch.Sirius.FtxWrapper.SwoxWrapper::FTX_CreateContractList(@"\\GFCFS02\BankFiles\CHTA\FTX");

    CodeAccessPermission::revertAssert();

    if (ret != 0)
        return checkFailed("@GFC2440");

    return true;
}:

The class is running on server

Who can help me out?