See https://forum.feed-the-beast.com/threads/rftools-liquid-monitor-does-not-see-enderio-fluid-tank.209913/

I also see this on my custom modpack with:

• Minecraft 1.10.2
• Forge Mod Loader (FML) 1.10.2-12.18.3.2185
• RFTools 1.1x-5.82
• EnderCore 1.10.2-0.4.1.65-beta
• Ender IO 1.10.2-3.1.156

Can see an EnderStorage Ender Tank next to it.

Did you report this to the EnderIO people? This is probably caused by them not implementing 'null' facing properly for their tank

Will be fixed in the next release of EnderIO

Thank you. :) I started here as there was also a thread mentioning it when I searched and Liquid Monitor is the device I want to use. I didn't see a similar thread nor bug for Ender IO, should I open one to track it? I found one where you talked with them about null facing, but that was for crashing the client, not Liquid Monitor (or similar) working and it was fixed/closed back in September 2016.

It is already fixed at their side and ready for next release so no need to open an issue with them

Awesome, thank you very much. :)