I had an app working good, but today it become empty. Disappeared everything - components, code, resource queriesa. I checked history - no changes scince yesterday. Super lots of bugs today
I got myself into the same situation before.
You can try the query param _historyOffset documented here to go back some changes.
What happened to me, was I created a dependency cycle that I was only able to fix by exporting my app to ToolScript, and manually removing the sidebar I made (that broke it) and importing it back in.
but its no cucles tyhere, i checked. There was several transformers and queries, but it gone. I mean list of code was not empty and it become empty) . i know that when it cycle it crashing and show empty screen, but all code still there
