Doorknocker UI stopped working.

I started using Doorknocker recently in my campaign. The players loved it so I added the feature to my campaign maps. All was well for a couple weeks, and then all doors on all maps ceased working for both players and DM. I have not changed the script and have not added or removed any other API since starting to use Doorknocker. I spent a lot of time adding this feature to hundreds of maps and would appreciate any help with this. I am new to API, so apologies if the solution seems obvious. 

Have you tried restarting your api sandbox ? You can open another browsing window to do it so you don't have to log out of your current session.

Did you copy or revert to a previous version?  Regardless doorknocker is not a heavy setup api.  Simply remove doorknocker api from the game, then go into the game and make sure that the doorknocker npc sheet is also gone(and make sure there are not duplicates which is what can fuck up the api and usually is the result of a copy of the game or a manual install of doorknocker on top of a normal install of doorknocker).  Then once the sandbox is rebooted, go and install it again, it will make the npc sheet again and you can adjust the color codes on the sheet to match your DL color themes and it should start working again.  Likely the culprit is probably just 2 doorknocker character sheets currently archived.  

It's also possible that walls and doors are coded with different colors than the ones you've been using. By default, Door Knocker uses blue for walls and orange for doors, to match the default used by Roll20-converted modules. If you started using Door Knocker on a module and have started doing DL with your own color choices, that would would be one explanation for a performance failure. Luckily, Doorknocker has the ability to adapt its color choice, or to adapt a page to meet its defaults. The details are in the Door Knocker character's Bio Page.

Yeah, I had a funny moment when I added Door Knocker to an Aliens adventure. All the walls were drawn with the default window colour!