I created an application and created a dateRange element. I tried to do the necessary calculations using the moment.js library, but it produced the wrong result. I decided to refresh the page and ended up with an empty app. after restore changes and several page updates, the apk resumed, but as soon as I decided to return the latest changes, everything happened again. I had to roll back the changes.
No see more issues. Component tree loadded, but showing nothing! Its not first time i met this king of issue. Please check
Be sure that you do not have the app opened in another window or screen or tab...
its 100% only one opened tab. This issue i met several time
In your Avatar on the top right there is an exclamation point ! Is someone else editing your app at the same time?
yeah, but as i told i met this issue not once and check alone, not only with my college. But it still appear for my college. He cleared cash, reload browser, but it happened to him every time
Looks like you have the app open in two tabs:
Can you try restoring an earlier version
i tried and it didn`t restore. I cloned a app to create this one. So even if i press to restor to first change - nothing
Perhaps log out and clear cache and log in again to Retool and see if that makes a difference - otherwise Email Retool support
Im trying to email support, but they not responding me) Maybe you faced such issue. We tried log out, clear browser data , log in again and still not loading app. Such error i got from browser console
From the Googles...
The full name of the error code is 422 “unprocessable entity.” In a nutshell, the error means that you're making a request the server understands, but it can't process it . Typically, this happens because there's a semantic error somewhere in the request, usually within a PHP or JavaScript file.
So somewhere in your code there is an error OR the API itself changed...
Hi there! I'm sorry to hear about all of the trouble with this app!
As Scott mentions, you have to be very careful about not having an app editor open in more than one tab/window. We are working on a feature called multiplayer that will soon allow you to have multiple people editing the same app 
Cloned apps don't typically have a lot of history since the history prior to duplicating the app won't be accessible in the new copy. That said, I'd recommend trying to step back in the history a little bit, as described in #4 here to see if that gets your app into a better state 
