This has been going on so long that I have a very hard time believing it hasn’t been reported here before, but the search function didn’t find anything for “temple” or “Dwayna”. Sorry if this has already been submitted.
The Temple of Dwayna meta-event frequently bugs – at least on Dragonbrand. After defeating the Priestess of Dwayna, Historian Vermoth normally approaches the statue, and the ghost of Malchor appears. This frequently fails to happen. When this bug occurs, the Temple of Dwayna meta-event does not restart and is impossible to complete until after a server reset or a new patch is released.
This bug is currently in effect on Dragonbrand. According to gw2stuff.com, the event has been in “Beat up Malchor” phase for the last 61 hours.