The door wont open when the shop is open but only when the shop is closed it will open.

I don't really know how it happens or how to fix it, but it's been brought up before - Try constantly opening it and closing it and trying to get the sign to be in sync with it

and/or

Try sleep/save/quit and reload to see if it fixes itself.  - maybe contact the other users on bug report megapost - and see what they were doing when it fixed itself.

I am having the same problem. Its either after I save and exit the game or after I sleep (idk), but when I try to open the door it does not work correctly. The door will only open inwards and make the open/close sign unreachable. However if the door is closed, I can change the open/close sign and but not be able to open and close the door. Its a game breaking glitch. I always have to restart and hope it doesn't happen again. 

I also have this problem, to fix it while the store is closed you open the door and while its opening press the closed sign. while the door will still open inward and you have to repeat it after every customer because they close the door, you can at least play

Hopefully this helps!

Saving and loading the game will also help.

I AM HAVING SAME PROBLEM IN TRY ALL BUT ITS STILL CAN'T OPEN SO I UNINSTALL THE GAME BUT STILL HAPPEN

TOAST732 THANK YOU ITS  WORKING. I AM IDIOT WHY I AM UNINSTALL THE GAME

No problem