gen already exists but is not a source folder. Convert to a source folder or rename it.

If anyone is getting this error in eclipse

gen already exists but is not a source folder. Convert to a source folder or rename it.

Here is how to fix it.

1. Right click on the project and go to “Properties”
2. Select “Java Build Path” on the left
3. Open “Source” tab
4. Click “Add Folder…”
5. Check “gen” folder and click Ok and Ok again
6. Again right click on the project and in the “Andriod Tools” click on “Fix Project Properties”