I'm not sure what's wrong. The characters in my party are on 14th level and for some reason they no longer accumulate experience points after defeating creatures. I would appreciate any help or info about this problem. Thanks!

This isn't a bug. This is a more or less intended effect. You see, according to the challenge/reward table, you aren't getting XP for defeating enemies that are considered too weak for you to grant any XP for defeating. This happens because your XP for defeating creatures of certain strength drops from level to level, you get less and less until you get no XP at all for those creatures which are too weak. That's what you get in D&D 3E rules. In NWN, you always get some XP, even if it's just 4 points. But not in IWD2. This is especially annoying for soloers, when the game starts to look like an adventure game rather than an RPG.

So yeah, getting no XP for some creatures at some levels is intended. Having to fight enemies that give no XP for defeating is probably not intended, at least not as a major thing. Alas, the reality is that you all too often get crappy XP or no XP.

In fact, while playing solo, you can get 0 XP after killing a dragon...but there are mods on this site that correct this...

Just fix the moncrate.2da file so that there are no zero cells and you at least get some reward for fights. Just don't make the XP rewards too large otherwise it's just silly.

Thanks for the quick replies!