Issue description:
The Fluidic Plenisher doesn't place lava properly. It places it likes water in lines, and "expects" it to autofill like water would do.
There was another issue, quite old (#4271), but you mentioned you couldn't reproduce it.
I did manage to reproduce it in a world with only Mekanism, JEI and WorldEdit (to easily make the testing hole), and ends up like this:

Is also an issue on 1.11.2.

In both pictures, the Fluidic Plenisher says that it is done.
I know 1.10.2 is an unsupported version now, but I hope it gets fixed there too.
Edit This is how it looks when the Fluidic Plenisher is just 1 block above ground (1.11.2):

The lighter lava blocks are still blocks, the rest are flowing
Steps to reproduce:
- Get a very large, flat area (tested with a 75r 80h cylinder)
- Place the Fluidic Plenisher in the middle, more than 3 blocks above ground. Provide it infinite power and lava
- Watch as it does around 3 big lines of lava, and "expects" it to autofill in, like water would.
Version (make sure you are on the latest version before reporting):
Forge: 12.18.3.2221 // 13.20.0.2345
Mekanism: 9.2.2.301 // 9.3.2.307
Other relevant version: WorldEdit 1.10.2-6.1.4 // 1.11-6.1.6 (I did test without WorldEdit+CUI too)
JEI
WorldEdit CUI
Issue description:
The Fluidic Plenisher doesn't place lava properly. It places it likes water in lines, and "expects" it to autofill like water would do.


There was another issue, quite old (#4271), but you mentioned you couldn't reproduce it.
I did manage to reproduce it in a world with only Mekanism, JEI and WorldEdit (to easily make the testing hole), and ends up like this:
Is also an issue on 1.11.2.
In both pictures, the Fluidic Plenisher says that it is done.
I know 1.10.2 is an unsupported version now, but I hope it gets fixed there too.
Edit This is how it looks when the Fluidic Plenisher is just 1 block above ground (1.11.2):

The lighter lava blocks are still blocks, the rest are flowing
Steps to reproduce:
Version (make sure you are on the latest version before reporting):
Forge: 12.18.3.2221 // 13.20.0.2345
Mekanism: 9.2.2.301 // 9.3.2.307
Other relevant version: WorldEdit 1.10.2-6.1.4 // 1.11-6.1.6 (I did test without WorldEdit+CUI too)
JEI
WorldEdit CUI