Continuum Rift?
In the Grove yes there is a current event which u can only see if you have finished HoT to avoid spoilers. The continuum rift you are seeing is part of a bug listed below, but it is often seen at the site of the current event listed above.
https://box.es/stonecold
https://www.librarything.com/profile/Randulf,
https://www.librarything.com/catalog/Randulf
https://www.librarything.com/profile/Randulf,
https://www.librarything.com/catalog/Randulf
(edited by Randulf.7614)
It’s a bug with one of the Mesmer’s skills.
https://wiki.guildwars2.com/wiki/Continuum_Split
Sanity is for the weak minded.
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