RFTools 7.12
Network tools GUI flashes briefly then disappears when wacked on some energy conduits carrying RF. If wacked on to the ground or some block, the GUI will appear but no useful information can be seen of course. Holding the item will show energy network, which I guess is part of the new behavior.

Same as the block protector issue, #1448. Single player works fine, only happens in multiplayer.

I cannot reproduce this. Are you using sneak-right click to open the GUI?

No, I just hold the tool in my hand then wack the cable. If the tool is held in the hand, I see an outline of all RF consumers. Whacking a cable with right click will make the GUI briefly appears then disappears.

What if you use sneak-right click?
That's how you're supposed to open the gui for it

Hm I just did that, sneak-right click. GUI flashes then disappears.

Why did you close this? Is it fixed for you now?

Same comment as #1448

This fixed the problem
SpongePowered/SpongeForge@a684ccc