Hi. I visited http://www.reachdowneast.com/calendar/events/community/add and it worked for me (no 500 error).
The links generated by your event settings page are, at the least, missing the separating forward slash before “community”.
1) Please let me know if you’re still experiencing any issue besides the bad links displayed on the event settings page.
FYI: I cannot reproduce the issue of the bad event settings page links, even if I change the “Events URL slug” setting from “events” to “calendar”.
2) If this is still happening for you, please follow our Testing for Conflicts Guide and see if that helps narrow down the cause of this.
Let us know what you find out.
Thanks.