Err=5

50% of the time I
A) switch districts
B)switch towns through map
C)or login
this error comes up.
Of course it works fine the remainder of time. I am hoping someone has information reguarding the cause and solution to this problem. Would be well appreciated.

Yeah, same thing happened to me four times; three times when I was at the merchant in Yak's Bend, and once when I was in my skill window.
I got "Err=5" as well as "Err=7". I have no idea what the cause is though.