The Eternity Vault operation has been bugged since the 7.2.1 64-bit update.
During the fight with Gharj, the stepping stones that fall between the platforms are invisible.
In the fight with Soa, some of the platforms are invisible. This makes it extremely difficult to survive the way down when the platforms are dropping.
We (my guild, pugs, and I) have encountered this bug multiple times since the update, both in Story Mode and Veteran Mode. I should mention that we are on the Satele Shan server, so I cannot speak for the other servers. I will also mention that some of us are running the SWTOR client while others of us are running the Steam client.
We have submitted bug reports several times that seem to have been ignored. One of my guild members also submitted a Customer Service ticket and she got the reply from SWTOR that it was "working on their end" and to just reset the phase.
We tried to do the raid again last night and could not complete it because the platform issue in the fight with Soa makes it very difficult to survive. BioWare, can you please fix EV? It's been three weeks and I have not even seen this appear on the list of known issues, much less any plans to fix it.