for the Nav bar error that I see on the picture -- lpulll up that templae page and make sure you add lauguage entery for that code.. also look at the code for the incvoice number and see if any other chars there if so remove .. then try to review that invoice see if that cleans up for you ...
over all i would make sure that for your lunguage the files are inplace and re check any edits for ie example
$invNumber = "Invoice Number:"; are done or in file accessable to your luaguage .. try site in nglish see if it works may help with some clues..
Jonathon