When Quark and Mekanism are installed together Mekanism machines will not process anything.

I ran a simple test by placing a basic smelting factory next to a creative energy cell and attempting to smelt cobblestone into stone.

With Quark installed the basic smelting factory would not process the cobblestone.

Beyond this, Quark seems to break the world file. Even after removing Quark, leaving only Mekanism installed and nothing else I still could not process anything in Mek machines. I had to create a new world each time I removed Quark.

Screenshot of install directory: http://i.imgur.com/hZ0PFWP.png

Test environment: http://i.imgur.com/J0ZDRag.png

Hopefully I am wrong about this. Mekanism users should stay away from Quark in the mean time as it will break Mekanism machines in your world.

After some additional testing with IC2 and EnderIO it appears Mekanism is the only thing being effected.

Just got back home from my wife's break. I'll edit this post with all of the information I've accumulated via testing in a little bit. Thanks for getting back to me, I hope it's a simple fix.

Edit:
Forge versions tested: 12.18.2.2171 (latest for 1.10.2)
12.18.2.2099 (latest stable for 1.10.2)

Mod versions are shown in the install directory screenshot above.

Steps to reproduce this bug.

Install Quark and Mekanism versions in screenshot.

Create a new world. You cannot use a pre-existing world, it must be a fresh world.

Power a mekanism smelting factory, I chose the basic smelting factory.

Place a stack of cobblestone in the machine's buffer. It will not smelt.

Exit Minecraft and delete Quark + AutoRegLib.

Load back into your world and attempt to smelt cobblestone again. You shouldn't be able to.

If you create another new world with just Mekanism installed your Mekanism machines should work fine.

I tested again alongside 57 other mods, the issue re-occurs when ever I re-add Quark.

Edit 2:

I should have checked, Quark seems to have updated a day ago. Version .64 works without issue. Version .63 breaks your world.

I'd still advise looking into this as what ever caused it may creep up again. I'm slightly apprehensive about about using Quark in the mean time as I rely heavily on Mekanism.

Sorry for the long winded post. I haven't worked with modded Minecraft in about a year so I'm a tad out of the loop.

Edit 3: Me and my friend were able to isolate the exact issue. You're appending metadata to ores and blocks.

Screenshot: http://i.imgur.com/7JhQ3Qp.png

You may wish to take down version .63 and send a message out for modpacks using .63. This will probably cause issues with other tech mods that don't ignore meta data as well.