I received no notice that staff wouldn't be on-site during my stay, so I arrived without a working phone in the EU (travel pass not turned on yet) during reception hours, only to find a sign indicating to call a number to check-in.
There was nothing open, no phones around and my taxi had already left I would have been completely screwed if someone hadn't come out to smoke and called them for me.
If reception hours are going to change or there are none, people should be informed. I choose hotels with reception open when I plan to arrive because I don't want to deal with issues getting in. It was a VERY unpleasant surprise. On the other hand, once I was in, the bed was very comfortable. They obviously keep it clean, but that included getting woken up by vacuuming before 8 am