It really just depends on the game with its resolution, textbox and text size. Some games the default 41 is too many and some can do 60 or more easily. If you really want to know how many can fit i would recommend testing without doing any wrap and then just count how many characters it displays before they run off the textbox. Then chop off a few just for larger characters and use that. You also have to be careful of any existing next lines in your translation already. If for instance your translation already goes on to a new line at character 60 and you put in a new word wrap at 40, then you may have a line that only has a couple words on it. Another thing to be careful of is that when you tell it to only put 40 characters on a line it will ONLY do that many. It doesn't care if that means putting a word one two different lines. Its frankly a rather blunt tool and is best used at the start of a translation project where you can correct things properly as you adjust the machine translations.
That done message only means its done with that single file. If its stuck at that point and waiting 5-10 minutes doesn't show any more progress its most likely crashed. You can try hitting F12 to open the console and see if its just showing an error message which will confirm that its frozen.
