Are you receiving any error messages such as "Bad Token" or "Failed to Connect"? You could try switching your rendering system by going to Options > Video > Rendering System.
It may be due to the fact that the map might be full or there is too many members entering the same map at a time. These issues tend to cause these crashes and it's fairly common with Fluorite Plains and Bonfire Island.
By moving your cursor to the right side of the Feralheart website it should tell you how many players are in a certain map. If the map is nearly full I would suggest trying to enter it maybe at a late time when their are less members.
Good luck!
