Cannot see parameter value in Android Studio when breakpoint is in first line of a method

Try turning off your jacoco test coverage off for the debug build in your build.gradle file:

debug {
    ...
    testCoverageEnabled false
}

This completely fixed the issue for me where upgrading the gradle plugin did not.

A good solution until AOSP Issue #123771 is solved, is to use the snippet provided by Stuart in the comments section:

buildTypes {
    debug {
        [...]
        testCoverageEnabled true
    }
    release {
        [...]
    }
    debuggable.initWith(buildTypes.debug)
    debuggable {
        testCoverageEnabled false
    }
}

This way you can both keep your test coverage reports in your debug build and have a way of stepping through code seeing your local variables.

I don't have in my gradle file:

debug {
    ...
    testCoverageEnabled true
}

but had the same issue on Android Studio 2.2. Solution that helped me to resolve issue:

1. Disable Instant Run in IDEA Settings.
2. Re-build project.
3. Enable Instant Run.