I've been running both NAV 2009 & NAV 2013 on my machine for testing purposes for a few weeks now without a problem. However, I attempted to make a backup of data in 2009 using the Classic client and got this error, "The backup cannot be used with this version of the program".
I haven't been able to find anything about it. I assume it has something to do with me having both versions on the machine. They are using different installs of SQL as well. Any ideas?