As we all continue to explore patch 3.1 on the live servers, there's bound to be bugs popping up, despite the work done by both Blizzard and players on the PTR. Blizzard poster Daelo has already created a list of known issues with Ulduar and is updating it as more information becomes available.

There is currently no fix for the fact that Siege Engines that use Steam Rush while on a ramp sometimes fall through the world. The two trash pulls in front of XT-002 Deconstructor are linked, but a soft instance reset should hopefully find the trash no longer present, although a full server restart might be needed. And they're currently investigating reports that players are being melee'd by Ignis the Furnace Master while in the slag pot.

Keep reading below for the current full post, and keep checking it for any updates. Have you noticed any issues that are not on Daelo's list?

Here's the current issues with Ulduar we're currently investigating.
UPDATE: 10:52 PM Pacific Daylight Time

Siege Engines that use Steam Rush while on a ramp sometimes fall through the world.
We currently have no fix for this, the workaround is simply to not cast Steam Rush on the ramps. The ability works fine in the Flame Leviathan fight and other flat ground.

The two trash pulls in front of XT-002 Deconstructor are linked.
UPDATE: We've disabled the XT-002 Deconstructor Trash, but the hotfix will not despawn currently spawned trash. A soft instance reset should hopefully find the trash no longer present, but it's also possible the fix might require a full server restart.

Shattering an Iron Construct in the Ignis the Furnace Master encounter does not properly reduce the number of stacks of Strength of the Creator on Ignis.
UPDATE: This has been hotfixed so that shattering a Construct removes one stack application of Strength of the Creator.

There are reports that players are being melee'd by Ignis while in the slag pot.
We're investigating this.

Issues with general instance server stability are also being examined.