SeleniumPlus (Eclipse) fails to launch! (SOLUTION)

On rare occasions, a crash of SeleniumPlus or a test launched by SeleniumPlus can leave Eclipse in an unstable state and it will fail to launch again.
The user has to look in the log that goes with their specified (workspace)\.metadata directory for possible causes.

Users have reported errors like:
==================  reported errors  ==========================================
    !SESSION 2016-08-15 10:46:40.849 -----------------------------------------------

    eclipse.buildId=4.3.0.M20130911-1000

    java.version=1.7.0_45

    java.vendor=Oracle Corporation

    BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=en_US

    Framework arguments: -product org.eclipse.epp.package.java.product

    Command-line arguments: -os win32 -ws win32 -arch x86 -product org.eclipse.epp.package.java.product -clean

    
    This is a continuation of log file C:\SeleniumPlus\.metadata\.bak_0.log

    Created Time: 2016-08-15 10:46:46.526


    
    !ENTRY org.eclipse.osgi 4 0 2016-08-15 10:46:46.526

    !MESSAGE Application error

    !STACK 1

    java.lang.NoClassDefFoundError: org/eclipse/core/resources/IContainer
=======================================================================


You can also check Google for Support Forum threads like:
www.eclipse.org/forums/index.php/t/156204/

Often, the simplest solution to this is:

• Shutdown SE+
• Delete the file .snap located inside the folder (workbench)\.metadata\.plugins\org.eclipse.core.resources
  
• Start SE+, IF PROBLEM DOESN'T RESOLVE THEN DO FOLLOWING STEP
  
• Delete the file workbench.xmi located inside the folder (workbench)\.metadata\.plugins\org.eclipse.e4.workbench