Android Studio "cannot resolve symbol String"

There is simpler and I think more correct way:

Just select menu item 'File/Invalidate Caches/Restart...'

For me this successfully resolved the issue (was caused by surprising power off of PC)

So project arrangement should be as follows:

• create app folder within your project.
• within app folder make following folders: libs and src
• inside src create main folder
• inside main create java and assets
• move contents of old src to java
• move contents of old libs to libs
• move res folder to src
• move AndroidManifest.xml to src
• move assets folder into src
• create build.gradle inside app folder with following content:

apply plugin: 'android'
dependencies {
compile fileTree(dir: 'libs', include: '*.jar')
}
android {
compileSdkVersion 19
buildToolsVersion "19.0.1"
}

• create settings.gradle in project root with following content:

include 'app'

• build.gradle in root should have following structure:

buildscript { repositories { mavenCentral() } dependencies { classpath 'com.android.tools.build:gradle:0.9.+' } }