This happened last Thursday, whilst I was trying to make use of a Premium day to level up (and hopefully get away from the eternal IoP GQ for once and for all).
I had just completed my second Nords (of hopefully 6), and was awaiting generals' return to island.
After clicking on the loot mail for the adv, the xp was sufficient to bring me to Level 42, and the relevant Level up popup appeared. The minute I clicked to accept the gems and gold, all hell broke loose.
I was bombarded with the popup and audio cues that the PH had completed an order (I had a very full queue that had been set earlier), this went on for quite a while.
When it finished, I naturally looked inside the Prov House, to be greeted by this image:
The entire queue had vanished, except for the very last item, which was showing 1 left to complete, but due in a negative amount of time.
I then looked in the star menu, some of the PH items were there, but ghosted out the moment they were clicked, whereas the loot from the adv acted normally. Something very wrong had happened.
I didn't dare leave the map or refresh the game, in case any evidence was missed before I could take a snap, and previous experience left me fearful of a server zone lockout, likewise I was warning guild mates not to visit island in case something corrupt locked them up too.
After a couple of hours mooching about, and occasionally checking Prov House to see if there was any change, finally the PH queue came back to what appeared to be normality. The buffs that were at the beginning of the queue were still gone, but the remainder of jobs appeared correct, and in the same order that I had placed them. Those items eventually did end up in star menu as per normal behaviour, once they were completed, I have no idea if the buffs got there or not.
By the time things got back to normal, I managed to start and complete another Nords, but by the time that finished, it had got very late, so I abandoned my quest for the night.
Getting in the next day, I just managed to scrape in a 4th with under 10 minutes left on the timer, but all the wasted time meant that I could not do the full set I had planned, or substitute the 6th one for a Lost Skull is times had got tight, and that has held me back from getting another level whilst using the premium.
nasty, nasty behaviour.
No buildings were being upgraded at the time, and no daft collectable buffs were being made in the mayor's House, all that was going on was the adv screens and the Prov House queue, and everything had behaved normally (apart from some shocking lag at times as is usual), until that Level Up screen appeared. That seemed to be the trigger.