Closed door
It is logical that children cry the first times they come to the play room, when we shut the door. Most of them are not used to closed doors, where they cannot get out.
It is very sad to see a small, helpless child cry to much -it can go on for quite a while, since we all know that they insist very much!- but it is good to think that really nothing unpleasant happens in there. They simply don't know yet, that they will have a marvellous time in there, that this place is an oasis for them. They stick to the idea that they want the door open and go out, and can't stand it that this is not going to happen. When they get over it, usually their mood and behaviour change immediately and then we can play!