2013 was pretty rough for me as well Ken, as well as January, 2014.
On the Users Online Today Mod, here's the deal. The following file operations didn't get done during the install. Those files shown below contain the missing language strings ...
Move the included file "lang/UsersOnlineToday.english.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.english-utf8.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.danish.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.danish-utf8.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.portuguese_brazilian.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.portuguese_brazilian-utf8.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.portuguese_pt.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.portuguese_pt-utf8.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.hungarian.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.hungarian-utf8.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.german.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.german-utf8.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.spanish.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.spanish-utf8.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.spanish_latin.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.spanish_latin-utf8.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.dutch.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.dutch-utf8.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.croatian.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.croatian-utf8.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.serbian_latin.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.serbian_latin-utf8.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.russian.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.russian-utf8.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.finnish.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.finnish-utf8.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.turkish.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.turkish-utf8.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.persian.php" to "./Themes/default/languages".
Move the included file "lang/UsersOnlineToday.persian-utf8.php" to "./Themes/default/languages".
Since you are only using only English here, the only one that is required is the one I bold-faced above ...
Move the included file "lang/UsersOnlineToday.english.php" to "./Themes/default/languages".
That file is missing from the default theme, Curve, as well as from the Workdesk3 and Argentum theme. However, it should only need to get copied to the default languages folder and the other edits should read those themestrings from there. I don't know why those file operations didn't get done during your install of the Mod, unless you installed it manually or something and forgot to move those files.
Jim