how to solve System.Drawing - Parameter is not valid

Question

when i use  code :

string img2 = "http://13.228.146.249:8080/jcr/groups/629.png;

byte[] toBytes = Encoding.ASCII.GetBytes(img2);

if (toBytes != null)

{

MemoryStream ms = new MemoryStream(toBytes);

ms.Position = 0;

picboxserver.Image = Image.FromStream(ms);

}

picboxserver is picturebox type.