Error:Unable to obtain debug bridge in android studio

After updating Android Studio to 2.0 l am getting this error unable to obtain debug bridge and Android Device Monitor does not open. Anyone faced this error before?

Where do I find Android Debug Bridge?

Enable adb debugging on your device To make it visible, go to Settings > About phone and tap Build number seven times. Return to the previous screen to find Developer options at the bottom. On some devices, the Developer options screen might be located or named differently. You can now connect your device with USB.

I just open sdk manager and installed all android sdk tools and done.

Check whether you need to install "Android Sdk Platform Tools" in the Android SDK Manager.

Somehow, after installing Android Studio from the bundle (for Linux) I lacked the "platform-tools" directory in "Android/Sdk", where the adb executable resides. Installing the platform tools helped. It was easier to find in the standalone sdk manager.