Sometimes ME autocrafting does derp up, but for others reading this thread, make sure you check your external crafting machines and encoded pattern recipes before writing this off as a bug.
Firstly, sometimes you might have a recipe that calls for a subpart that the system thinks it can make but actually can't, due to faulty or improperly located recipe patterns in your ME interfaces. For example if you're trying to autocraft something that requires an "iron dust" item from Mekanism, and the system sends an iron ingot to be pulverized by a Thermal Expansion Pulverizer, you will end up with a Thermal Expansion "pulverized iron" item. In most cases this is fine, due to the ore dictionary, but the ore dictionary isn't perfect. I've come across scenarios where AE treated items like this as not equivalent and thus the crafting process hangs there waiting for one item, even though the item was already processed and just doesn't realize it because the item it got back was not the item it was expecting. So make sure the recipes you put in your ME interfaces are accurate. You won't get a Mekanism iron dust from a Thermal Expansion Pulverizer.
Secondly, if any one of your external crafting machines is hung up for any other reason, your ME system will legitimately be stuck waiting for an item to be crafted or smelted or whatever. For example, I couldn't figure out why a bunch of Mekanism items weren't being crafted. I eventually found that these items were relying on iron ore to be processed through my Mekanism quadrupling setup into iron ingots, and one of the intermediate machines was not set to auto-output. So all of the iron shards or whatever were just not making to the end of the line and back into the ME system as ingots. However this can also happen if one of your machines simply loses power or is bugged out for any other reason.
That being said, there are occasions where my crafting monitor/processes just hang for no apparent reason.
I had the same problem and found this thread on google.
Also managed to get it working but I thought I could share what helped me for people who might have the same issue.
I broke a cable which connected my ME terminal, ME c-terminal and ME crafting monitor to my network and that fixed the issue immediately.
Reconnecting the crafting monitor is enough. I have mine connected with a dark cable. Facade on it and a carpenter's button set to inverse. If crafting derps, I just hit the button and everything works again.
Thanks this is brilliant. Breaking a cable and thus causing the system to refresh itself seems to fix the problem for me as well. Using a button/lever with a dark cable achieves the same result, and is quite convenient. In general I already like to keep major subsystems of my network (DSUs, or autocrafting) on their own cable segments so I can potentially disable them if necessary. So this works out nicely.