Unbound classpath container: JRE System Library [JavaSE-1.7]

If you are getting "Unbound classpath container: JRE System Library [JavaSE-1.7] in project proj Build path Problem" in Markers Console in Eclipse when you create a new J2EE Dynamic web project, then the reason can be that JavaSE-1.7 classpath is not set or some other version of Java SE is available.

1. Right Click on your Project Folder,
2. Properties → Java Build Path
3. Goto Libraries tab and check if there is an error in JRE libraries.
4. Click on Add Library and Select JRE System Library, click next
5. Click on Installed JREs and add the JRE available (in my case I have JRE 8 installed). If you don't see any JREs here you are supposed to add one.
6. Click OK and finish and the error must go!