Solution 1:

This problem has been encountered in Skyrim by someone on the Steam forums, too, although in this user's case it's a dollar sign '$' prefix instead of an 'S', and it wasn't caused by an edit. Since Skyrim and Morrowind use very similar editing tools, I suspect the problem has similar causes.

Here, the problem was solved after validating the game files through Steam, and (inadvertently) changing the game's language.

Apparently, the cause of this bug can be located either in the .ini files of the game, or the localized language files (which seems less likely).

I suggest backing up your Morrowind.ini (from C:\Program Files (x86)\Steam\steamapps\common\Morrowind\, C:\Program Files (x86)\GOG Galaxy\Games\Morrowind\, or C:\Program Files\Bethesda Softworks\Morrowind\), and removing it. Then, either by restarting the game, validating the files through Steam, or copying the file from your installation CD, reinstate the original default .ini.

If that doesn't fix the problem, changing the language might. First, change it to anything, then back to your preferred language. To change the language

  • in Steam, right-click the game in your library, and select 'Preferences'.
  • using GOG, go to the game's page in GOG Galaxy, click on 'More', then 'settings'.
  • if you have just the disc with the game files, it will be harder, so I suggest a complete reinstall.

As per your comment, the asterisk in front of the fEncumbranceStrMult string denotes an edit in the Morrowind Construction Set.