When both Mekanism and Thermal-suite mods are installed Mekanism's steam conflict with Thermal's Steam and throw a lot of error, in addition after restarting your server you can't pump steam into Thermal Expansion's Steam Dynamos anymore.

https://youtu.be/XUhPb827HW4

Server Log: latest.log

Minecraft: 1.12.2
Forge: 2659
Mods: list.txt

I don't see how this is a problem with Mek, as Mek always queries the FluidRegistry to make a steam FluidStack, so it will use whichever variety the world decided was to be used.

The errors in the log are related to HWYLA, and even if it is Mek steam, I don't see how it would fail as we use the standard Fluid object.

Talk to KingLemming, I don't know enough to comment on what's happening.

That sounds more and more like thermal isn't using the fluid registry properly. Multiple mods register fluids and the registry decides which one should be used.

Mekanism uses it properly as it does not cache a fluid reference.

I'm telling you it can't be Mek's fault.

Edit 3: It's on TEs end. Thermal expansion doesn't accept ANY steam unless it's added by thermal expansion (IE bucket of steam says "Added by thermal expansion")

Can confirm this is happening. Removing Mekanism makes them work again.
Other mods producing steam are installed and don't conflict with Thermal expansion.

Edit: I should specify when using a Thermal expansion steam producer and a steam dynamo hooked directly into eachother doesn't put the steam into the steam dynamo, unless mekanism is removed.

Edit 2:It's specifically if the bucket of steam is "added by mekanism" instead of "added by thermal expansion"

It is indeed something I re-introduced in TE. I had solved this before, was told to move it to FluidStacks for delegate reasons and apparently that was incorrect.

@KingLemming caching fluid stacks is ok, as long as you invalidate the cache on world load, as the fluid you get during pre/post/init may not be that same as what the world uses.

e.g. adding a mod to an existing world that happens to register the same fluid earlier than the existing mod will trigger this, as the world load will choose the pre-existing fluid as the default