Hakumi you're so quick to reply you beat me to it XD
Could it be possible that you may be missing the Cherika Valley map from your files?
If not missing, then it could just be that there are way too many people in that map for your computer to handle. Cherika has kinda become a very popular spot, and last time I was there I had major lag in one area of the map due to there being so many people in one place. If it's possible for you, wait until later when activity has maybe died down.