We have an issue on our server, the essentia storage monitor cannot be placed. Right-clicking it on a cable just does nothing. It works fine in SSP with the same pack, just not on the server.

Version: 0.8.10.5

I'm not sure whether you need more information, just tell me if you do =)

Confirming same issue.
Also Running v0.8.10.5 (FTB Infinity v1.6.2) and cannot place down Essentia Storage Monitor on any/all ME Cables.

So far I have not been able to reproduce the issue in my dev environment or with a fresh install of FTB Infinity 1.6.2
I have tried both the conversion monitor, and storage monitor, with and without a security terminal attached to the system.
Is it possible to place the monitor at all? If so, try placing it down, then placing a cable against the back.
I will continue testing to try and reproduce this, in the mean time please let me know if the above works for you.

I forgot to mention that I already tried that. Placing the monitor down without a cable makes the breaking glass sound and doesn't work as well.
It also doesn't work on an isolated cable (I was considering it had issues with the security station on the system, but apparently that's not the issue).

Update: Bug appears to only exist on multiplayer server

Testing Steps:
In a single player game (fresh install of FTB Infinity 1.6.2) I was able to place down an Essentia Storage Monitor just fine on a basic AE2 system.

Using the same Fresh Installed client: I connected into my normal server and still couldnt place down ESM on my existing AE2 system
Setup the same basic AE2 system that worked before in single player game: Still could not place down ESM while on my server

Setup a fresh new FTB Infinity 1.6.2 server (no configs changed all defaults): Could not place down ESM on the same basic system

BASIC SYSTEM SETUP:
Advanced Solar Panel -> Engery Accepter -> Dense Storage Cell -> ME Controller -> ME Drive with 64k Drives inserted (essentia and normal drives) -> Smart Cable -> Essentia Storage Monitor

I hope that helps shed some light on this bug.

Has someone tested if this issue occurs on a minimal client + server? (only TC4, ThaEn and AE installed)

Also running v0.8.10.5 with the same issue here as well. Seems to apply to the Essentia Conversion Monitors too. They work properly in single-player, but when I try to place either in SMP they just make the breaking glass noise no matter where you try to place them; cable, block, or otherwise.

Rather suddenly this started happening in my Infinity 1.6.2 test world, the error log shows that the server-side is trying to access a client-side only field. No idea why this doesn't always occur, but I will get it patched up.

I confirm this bug, using ThaumicEnergistics-0.8.10.5.jar and appliedenergistics2-rv2-stable-9.
I am not able to place the Storage Monitor on Smart/Glass cabling, and when placing on Dense cabling it makes the Breaking Glass sound.
I am using this packlist: http://pastebin.com/V8NZG9Yd (Project Gamma)

I have this fixed in the code, but I have not yet pushed out a new build. I got caught in the middle of a pretty major under-the-hood overall, when my summer semester decided to take up most of my time. But I will try to get it wrapped up and push a new build this weekend.

I really hope this gets updated soon! I want to get it back on our server working properly. Side note: I hope its also updated for the latest forges versions, like .1408+

Build 0.8.10.6 fixes this issue.
http://minecraft.curseforge.com/mc-mods/223666-thaumic-energistics/files/2245337

I see you have submitted a new build recently. Did it include this fix? I hope so. I am excited for it.

I've not yet completed the 0.8.10.6 build, but the fix is in there.