Your Challenge, if you choose to accept it, is to make the 1815 Treaty of Paris the 19th Century analogue of the 20th Century Treaty of Versailles and not have it be ASB. Then what will happen?
The trick about "powderkeg treaties" is to take away enough to anger a country, but leave enough intact for them to remain dangerous.
So for the treaty of Paris I would say at least take away the French colonies. Give the Netherlands French Flanders and Hainaut and you know what, for fun give them Artois too. France loses the Alsace (to Baden?), Mulhouse and Pays de Gex to Switserland, Roussillon to Spain and Corsica to Savoy. Especially the last one is a big insult to France, as its emperor came from Corsica.
Those things are all still pretty small and probably not enough for a "powder keg treaty". France is not happy, but I don't think it is enough for them to go on a rampage of revenge. You need more. Maybe an independent Lorraine and/or Brittany. Would that weaken France too much? Large payments to the allied nations and a long term occupation of French teritories would help too.
Still that won't happen in 1815. Nobody wanted that, for good reasons. So you need an earlier POD. Maybe even Napoleon manages to defeat Wellington at Waterloo, afterwards defeats the Prussian army and is then defeated by the Russian and Austrian armies. People now want to realy punish France and give it a lot harsher treatment.
Anyway, what could happen next? France gets more involved with the Belgian revolution and manages to annex (part of) Belgium? France manages to reabsorbs Lorraine (which wants to be French anyway) and recapture Britany?