The data to be decrypted exceeds the maximum for this modulus of 256 bytes.
What I have tried:
Public Function Decrypt(ByVal encryptedText As String, ByVal cert As X509Certificate2) As String
Try
Dim privateKey As RSACryptoServiceProvider = CType(cert.PrivateKey, RSACryptoServiceProvider)
Dim encryptedBytes As Byte() = Convert.FromBase64String(encryptedText)
Dim decryptedBytes As Byte() = privateKey.Decrypt(encryptedBytes, True)
Dim decryptedText As String = Encoding.UTF8.GetString(decryptedBytes)
Return decryptedText
Catch ex As Exception
End Try