Broken ATN Spinnaker Sock Block

A couple of weeks ago, we had a try at the cruising spinnaker. The conditions were perfect with light NW winds. Our cruising spinnaker comes in this ATN spinnaker sock, which no one onboard was familiar with. We have flown traditional spinnakers before, with a turtle, topping lift, downhaul and sheets, but never a spinnaker with a sock before.We connected the spinnaker halyard to the head of the sail/sock. Then, we hoisted the sock with the sail in it. We connected the tackline to the bow roller since it is forward of the bow pulpit. We had attached two blocks at the stern, to control both sheets and ran the lazy sheet in front of the headstay. We hoisted the sock halfway up, and started to run into some resistance, so we lowered the sock and tried hoisting again. This time we noticed some fuzzy bits flying out of the top of the sock. We all agreed that this was probably not a good thing, so we lowered the sock on deck. There is a block at the top of the sock that has a loop running through it. Apparently, the line that is used to hoist the sock, must not be cleated or secured tightly (which is exactly what I did). This made the line come out of the block and start to chafe on the frame of the block. I contacted ATN and they sent me a replacement, which has already been installed. We tested raising the sock at the dock and it went up no problem. We'll have to try using the cruising spinnaker again soon!