I know I saw something about this earlier, but can't find the thread.
I just installed the mod after an OS upgrade. I started my game, but the population growth is (+4000) or something close to that. If anyone can tell me how to fix it or show me a link to the fix, I'd appreciate it.
You have a compatibility issue. WWM's download thread specifically states it is not meant for the 4.1 patch of HttT.
That is a guide to make your copy compatible with the 4.1beta patch (april). There are reports, and even on my machine, that it does not work with the newest official patch though.
The newest version of WWM (not released) seems quite good. BUT, the devs sorta broke something and thus the mod will not work at all until they release the next patch (they've said they'd fix what they did). So, the newest version meant for HttT is currently sitting and waiting.
Some work has already begun on WWM for DW.