I am getting that error alot as well. Says I need to run the batch file in the tattle directory to copy the realm data. But have done that it is there already.
Well, I still see data for people from my and other realms, if they are nearby. Otherwise it fails.
The faulty piece of code is here:
local playerrealm = GetRealmName()
if UnitIsPlayer('mouseover') then
local n, r = UnitName('mouseover')
r = r or playerrealm
self:Print('realm:'.. r) -- debug
self:Print('plrealm:' .. playerrealm) -- debug
... do stuff ...
If player is in the raid or party, whenever I mouse over a party member who's out of line of sight.. say 40+ yards away or in another city, the previous piece of code fails and r contains a blank value.