PKCS11 method c_sign returned 2147483768

[geekforgee...@gmail.com]

Dear All, 

I am using pkcs11 interop to sign a xml content, query the device with Luna cyptoki . I am able to open session and and sign a message but when I am trying to sign a bigger file I am getting exception as Method C_sign returned 2147483768.

I am using SHA256 RSA mechanism  and using Session.Sign(mechanism, privatekeyobjecthandle, inputstream, bufferLength {8})

The file size is 1kb when its able to sign but when it increases 2 kb it fails.

Can some one please guide me on this