Thank you for making note of what you already tried. That helps a lot!!
Do you have a backup of your game-save just before heading off to France? If so, try that save. However, if you don't have a previous game-save. Try this:
1. Either copy the meta.data file from an existing save or start a new game, go into Edit Town and Save and quit the game, then copy the meta.data file from the new game.
Note: Adding a new meta.data file may change your loading screen. But you can fix that once the game is loaded by saving the game.
2. Paste the meta.data file into your current game save. Then try playing it.
3. Play a few minutes before you go traveling - to make sure game is working okay. Then use Save As (for example) France1. Afterwards, go to France.
4. When you get back from France Save As again with a new name.
If you can play it, play the game for a few minutes and then use the Save As option, give it a new name. Then save and quit.
Hope this helps,
MrsFlynn
Reference Link:
http://simswiki.info/wiki.php?title=Game_Help:TS3_Load_Issues#A_Serious_Error_has_occurred_error