My understanding is that the verb ある describes where something is, which means に is the correct particle to mark location. However there have been several cases I've come across where ある's location actually uses で:
(Requesting vacation time from a boss) あの、実は来月、私の国で姉の結婚式がありまして...
日本ではよくある - be common in Japan
I know I've seen more, but I'm struggling to find more at the moment. If more examples would help let me know.
Is this related to how we mark location with で in noun/adjective sentences somehow?