Custom event deploy on production : There is no code, which can be deployed to Backendless.

Hello. I try to deploy my custom event to production via
I generate and download source code from custom event console, do something in handleEvent method, and now try to deploy it. I obtain next error:
[INFO] CodeRunner™ Backendless Debugging Utility
[INFO] Copyright© 2016 Backendless Corp. All rights reserved.
[INFO] Version: 3.0.0 Build date: 20160219-0848
[INFO] CodeRunner session is running for 2 hour and will be terminated on 15:51:20.929[UTC]
[INFO] Registering runner on: with secretKey: *************
[INFO] Runner successfully registered
[INFO] Parsing event model…
[INFO] Build successfully: 0 handlers, 0 timers
[ERROR] There is no code, which can be deployed to Backendless.
[INFO] Debugging Utility disconnected successfully
[INFO] Thank you for using Backendless
P.S. I check my app ID and secret key for coderunner in, they are correct.

P.P.S. I use android studio

CodeRunner looks for the code to deploy in the “classes” folder which should be located at the same level as the “bin” and “libs” directories included into the CodeRunner SDK.

Here’s a brief video which shows how to set it up: