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Facebook library project is showing error but there is no error inside the project

I'm trying to run one of my old android project (Eclipse project).
It uses Facebook lib, google-play-services-lab and android-maps-util-master.
Both Facebook lib and my project MyanmarWatch_ is showing red ! on them.
I don't know how to fix since I don't see any error within them.

I got solution. I just forgot to check Java Build Path. 2 jar files are missing and I imported them.

Importing library in Android Studio

I have little experience with importing libraries. I am using Android Studio, and am trying to use parse.com's library with no luck. I followed these instructions, and tried a few other things when that didn't work. Please help me out. Let me know if you need any more information. Thanks for your time.
This is my MainActivity where I would initialize my Parse client key:
Project Structure showing I have imported the libraries:
UPDATE
Gradle:
UPDATE:
When I try to Build, I get this error: Gradle: error: package com.parse does not exist
When I try cleaning through command prompt

Put the jar into the libs folder
Right click it and hit 'Add as library'
Ensure that compile files('libs/~~~~~~~~.jar') is in your build.gradle file
Do a clean build (You can do this easily in android studio but just as a better method, go to your project folder using windows explorer and open a Command window there by right clicking the folder while holding shift and type gradlew build.

To add to the answer of #ThePoloDoc and for your update Command Prompt image, you need to do the following to clear that error:
Go to Control Panel -> System -> Right Side see for Advanced System settings
Select Environmental Variables
In the new window, search for the PATH variable. Add the java installation folder something similar to C:\PATH_TO_JDK\bin
Replace the PATH_TO_JDK with the installation of your java directory
Try opening the command prompt and you'll see the error gone.
UPDATE:
I have got a doubt in your question. Why do you manually compile gradle? I use Android Studio. But I always click the Sync Project with Gradle Files button on the top. It does everything for me

Android Phonegap 2.5.0: Error in building phonegap project

I've done to create a phonegap 2.5.0 project template by following Getting Started with Android on Windows.
I'm using the ADT Bundle IDE from Get the Android SDK. After I setup new Android project from existing code, I get few errors that prevent building the project. I've solved AndroidManifest.xml, main.xml, strings.xml, config.xml. But I'm still getting the major error which is
Archive for required library: '~/libs/cordova-2.5.0.jar' in project 'xxx' cannot be read or is not a valid ZIP file
Does anyone facing this problem before?

To make things easy, you can create the project by using the command create provided with the phonegap package. Once created, you should be able to directly compile it without any errors.
To answwer your question, make sure you have cordova-2.5.0.jar in your libs. If not, add it using right click on project -> Build Path -> Add external archives. Then choose the jar.

Paypal Mobile Express Checkout Library sample app gives me NoClassDefFoundError Exception

I'm testing the sample app for Mobile Express Checkout Library with Android.
I'm getting java.lang.NoClassDefFoundError: com.paypal.android.pizza.ResultDelegate
The error is on this Pizza.java line: PayPal.fetchDeviceReferenceTokenWithAppID(this, appID, server, new ResultDelegate());
I'm confused, i didnt find any info about that error on google, and also on the faq on paypal and x.com, so i don't know how to solve it.
I simply opened the sample code project and executed it.
This is the link to the project and the library: https://www.x.com/sites/default/files/PayPal_MECL_1.0_Android-Developer-Package_0.zip

There are only three reasons you will ever get this error:
The class genuinely doesn't exist. If you are using code from an official example and getting this, make sure you have the latest build of the library
You have not added the jar to your build path. To fix this, right click on the jar in Eclipse, and do Build Path ► Add to Build Path.
Your jar is not in the /libs folder. This happens when you have added the jar to the build path, but newer versions of ADT need it to be in /libs. Put it there and it will automatically be added to the build path. If it isn't, try doing a Clean build via ant clean or Project ► Clean in eclipse.
Mostly, such errors occur because newer versions of the ADT require all external jars to be in the libs folder.
By looking at the project you linked to, I can see the paypal jar in the project root. Instead, try moving it into a /libs folder. This should solve your problem.

I think you have not exported library jar from the configure build path section of eclipse.

create libs directory in project's directory and add move PayPal_MECL.jar to /libs. goto project properties and remove existing PayPal_MECL entry from libraries

Cannot Reference LVL Android Library in my App Project

I'm following the instructions found at http://developer.android.com/guide/publishing/licensing.html
I made a copy of the <sdk>/market_licensing directory, then using the New Project Wizard in Eclipse I created a new Android project from Existing source and pointed it at the library subdirectory in my copy of market_licensing.
I've checked the "is Library" box in the market_licensing project android properties.
I've added that project as a library project in my app project. It shows up in the list with a green checkmark.
When I save the project settings and rebuild, the compiler can't find the classes in the LVL project and when I go back into my app's project settings the entry in the libraries list now has a red X instead of the green checkmark.
I don't understand what I'm doing wrong which is preventing me from referencing the LVL project. Any help?
EDIT: I've tried adding the licensing project to my build path for my app project and then I'm able to build, but when I try to run the app crashes because it can't find any of the library code. So clearly the "library" status of the licensing project is not set up correctly and/or its not being automatically injected into my app project on build.

I was posting up a similar question and as I did so realised what the problem was - see here In eclipse, unable to reference an android library project in another android project