ERROR - org.eclipse.core.internal.resources.ResourceException: The resource tree is locked for modifications

Problem -

RAD doesn't start and displays the error upon loading workspace.

Resolution -

Trial 1 - Try opening some other workspace and then switch to the problematic workspace.

Trial 2 - Delete .Lock files within workspace\.metadata and then try to open the workspace.

Trial 3 - Take a backup of .profile folder within workspace\.metadata and then let another .profile folder get created and then copy of backed up .profile folder to new folder. ( This could be risky so do it with caution )

Trial 4 - If nothing works better get a backed up .metadat folder ( if any ).

If nothing above work , you may have to build the workspace again.