Recently I started an Urban Terror 4.2 server and saw that a new release had just come out the "002" update. So I updated the server before testing it and updated the client and when I tried to log in (without auth) the server gave me this error message:
Server uses protocol version 70
My first thought was that something didn't go right in the update so I solved the problem like this
1. Deleted the Quake3-UrT.x86_64 (I run Ubuntu 12.04 64bit)
2. Opened the UrTUpdater
3. Downloaded the file via the Updater
Done. No more error messages. My friend had the same problem and solved it the same way (he runs Windows 7 64bit).
Server version, date and name (for those who want the info)
name: q3urt42
version: 4.2.002
date: Sep 25 2012