Building process on Android has generated an error: "Building to the Assets folder is not allowed".

Hi

I moved my project from 5.4.1f1 into 5.5.0b10 beta.
At the moment there is no red errors in console, before to run "build and run" process.
When the device has been found, process building has stopped, generating an error like that: "Building to the Assets folder is not allowed.".
When I tried to build new project , there is no errors, so I'm confused.

Thanks

PS
I already have reported the bug report.

 

The issue is solved .

When I have been asked where to write the "apk" file I chose main folder of my project.