[DjNDB]

You mean Episode, not Season. That issue is often fixable and is usually caused by having multiple prefs.prop files, which sometimes happens for unknown reasons.

PC:
There should be only one prefs.prop, and that's in the savegame folder:
Win Vista/7: %USERPROFILE%\Documents\Telltale Games\The Walking Dead\
XP: %userprofile%\My Documents\Telltale Games\The Walking Dead\

If you run TWD in compatibility mode for win95 or win98/me it might save to:
%PUBLIC%\Documents\Telltale Games\GameData\
or
%PUBLIC%\Documents\Telltale Games\The Walking Dead\

Please open the games install folder.

To find the install folder from within Steam, right-click "The Walking Dead" and select "properties".
Then open the "Local Files" Tab. There select "Browse local files".

Please check if there are additional prefs.prop files in the install folder or its subfolders.
If so, make a backup copy of the prefs.prop and delete it from the install folder.

Now try the game.

If that doesn't help try the steps below.

If you are playing through steam, you first need to disable steam cloud for TWD (In Steam, right click TWD and select "properties". Open the tab "updates" and remove the checkbox from "Enable Steam cloud synchronization for TWD").

Then make a backup copy of the savegame folder's prefs.prop, and then try copying the install folder prefs.prop to the savegame folder.

Mac:
There should be only one prefs.prop, and that's in the savegame folder:
~/Library/Application Support/Telltale Games/TheWalkingDead/

Please navigate to the folder containing the games app package (TheWalkingDead.app).

If you're playing on Steam, right-click "The Walking Dead" and select "properties".
Then open the "Local Files" Tab. There select "Browse local files".

Right-click (or CTRL-click) on TheWalkingDead.app and select "Show package contents".
Please check if there's a prefs.prop in TheWalkingDead.app/Contents/Resources or its subfolders.
If so, make a backup copy of the prefs.prop and delete it from the TheWalkingDead.app package.

Now try the game.

If that didn't help try the steps below.

If you are playing through steam, you first need to disable steam cloud for TWD (In Steam, right click TWD and select "properties". Open the tab "updates" and remove the checkbox from "Enable Steam cloud synchronization for TWD").

Then make a backup copy of the savegame folder's prefs.prop, and try copying the prefs.prop from the TheWalkingDead.app package to the savegame folder.