Hi MotSmart
Find enclosed a short tool which check that no labels are useless or forgotten between english file and any other language file.
Open the file and set the two variables for your own local environment.
You could use it for any language file (not only for the installer)
With this tool unfortunately I found an issue in the english file (a carriage return was missing so the $_lang["checking_mysql_version"] assignment has been taken as a comment on the previous line.
The first screen capture (french file test) below show this result.
I have done some other tests on Norwegian file
(downloaded here) and Bulgarian file ((downloaded this morning)
Find enclosed the results.
Sylvaticus and WildRose sorry for the english typo ($_lang["checking_mysql_version"]), this generate an issue too in your own language file.
I will post the updated english file later [Edit: see rev 3734]. To correct the english file simply, line 161 add a carriage return before $_lang[checking_mysql_version] ... and remove the blank line 168.