Can't run app projects on Android Studio

Question

I am new to Android Studio, and I installed it on Ubuntu 14.04 LTS (64bit).

When I open the project in Android Studio, I get my project files marked with red and the debug configuration button beside the run button is marked with red X as shown in the below image:

Please tell me how to solve this issue.

Answer 1

The best way to resolve this issue is as follows:

• Clean and then rebuild your project

• Make your project (it should work by now)

• Check your dependencies in gradle

• At the very end you can try invalidating the cache and restarting (Recommended)

The problem should be resolved by now.

Answer 2

One of easy ways:

1. Close your currently opened project to go back to the welcome screen.
2. Choose Import Project (Eclipse ADT, Gradle, etc.) from the welcome screen.
3. Select an Eclipse ADT project to be imported.