Help Getting a error message

[KolorzRich]

Sometimes on my HTC Desire when I'm trying to reply to a text message with words or with a mms it tells me me that the destination address is invalid.

Then when I type in the 10 digit number or 11 digit number it says the same thing and never ends up sending.

HELP!

 

[takeshi]

Using the stock app? Details do matter for those trying to help you.

 

[KolorzRich]

What's a stock app? I'm not using any application for anything.