"App not found" error message in app previewer

[dbaum]

In the midst of working on an app today, the following disconcerting message suddenly appeared in the app emulator. I continued to be able to edit and save the app, but the preview didn't appear and the error persisted. I happened to have the actual app (i.e., not the editor) open in another browser window, where it continued to work fine--including reflecting the updates I saved via the editor.

I found a few posts about this error, with replies suggesting help from AppSheet support is needed or a reminder to confirm you're signed in with the right account.

In my case, I simply closed the browser tab with the app editor and re-opened the app from my account page. Then, the app appeared as it normally does in the preview emulator. So, if you've found this message because you're seeking guidance regarding this error, you should try closing and re-opening the editor.

Screenshot of  “App Not Found. The app you’re looking for isn’t here. Try contacting the app owner who sent you the link” error

[DroidTeo]

I had the same issue as you once.. on my side, I "solved" logging out and sign-in again.