Android Studio and android.support.v4.app.Fragment: cannot resolve symbol

Question

I am tryng out Android Studio instead of Eclipse. I install it and then start a completely new project and follow the wizard. I add no code of my own.

Then, I right-

Answer 1

Hrrm... I dont know how many times this has happend so far: I test, try, google, test again and mess around for hours, and when I finally give up, I go to my trusted Stackoverflow and write a detailed and clear question.

When I post the question, switch over to the IDE and boom - error gone.

I can't say why its gone, because I change absolutely nothing in the code except for that I already tried as stated above. But all of a sudden, the compile error is gone!

In the build.gradle, it now says:

dependencies {
    compile "com.android.support:appcompat-v7:18.0.+"
}

which initially did not work, the compile errors did not go away. it took like 30 min before the IDE got it, it seems... hmm...

=== EDIT === When I view the build.gradle again, it has now changed and looks like this:

dependencies {
    compile 'com.android.support:support-v4:18.0.0'
    compile "com.android.support:appcompat-v7:18.0.+"
}

Im not really sure what the appcompat is right now.