Could be a few things, the one I encounter the most is simply not waiting long enough. NPCs only periodically check to see if there's a new package to start doing, in order to make sure that's not the problem you can use the console, click on the NPC with the package and type "evaluatepackage" which will force the npc to check for a new package right away. - Does the package have conditions and are they met? - Is there another package which conditions are being met at the same time but higher in the list? (The top one will take priority) - Is the NPC being interrupted by anything? Check the Clear All Interrupt Flags in the Flags tab and try and check the Must Complete box so it doesn't try to finish early. See if any of those work for you.