Converting Stream to String and back...what are we missing?

I have just tested this and works fine.

string test = "Testing 1-2-3";

// convert string to stream
byte[] byteArray = Encoding.ASCII.GetBytes(test);
MemoryStream stream = new MemoryStream(byteArray);

// convert stream to string
StreamReader reader = new StreamReader(stream);
string text = reader.ReadToEnd();

If stream has already been written to, you might want to seek to the beginning before first before reading out the text: stream.Seek(0, SeekOrigin.Begin);

This is so common but so profoundly wrong. Protobuf data is not string data. It certainly isn't ASCII. You are using the encoding backwards. A text encoding transfers:

• an arbitrary string to formatted bytes
• formatted bytes to the original string

You do not have "formatted bytes". You have arbitrary bytes. You need to use something like a base-n (commonly: base-64) encode. This transfers

• arbitrary bytes to a formatted string
• a formatted string to the original bytes

look at Convert.ToBase64String and Convert. FromBase64String