Unable to load plugins; ClassLoader error

edit

I have created a plugin to test some changes that I will make in the exploration algorithm later. But, I am unable to load the plugins which I created. When I run my launch file, it calls for this plugin, but I get the following error:

[ERROR] [1446688037.439927809]: Failed to load exploration plugin! Error: MultiLibraryClassLoader: Could not create object of class type NearestBasedAllocation as no factory exists for it. Make sure that the library exists and was explicitly loaded through MultiLibraryClassLoader::loadLibrary()

In my package.xml, I am using export tag to link to frontier.xml:

<export>
    <nav2d_navigator plugin="${prefix}/frontier.xml" />  
</export>

While in frontier.xml, I am giving a brief explanation about my class

<library path="libFrontierPlugins">
    <class name="NearestBasedAllocation" type="NearestBasedAllocation" base_class_type="ExplorationPlanner">
        <description>
            Performs simple, uncoordinated nearest-frontier exploration.
        </description>
    </class>
</library>

My CMakeLists.txt file:

cmake_minimum_required(VERSION 2.8.3)
project(frontier_exploration)

find_package(catkin REQUIRED
    COMPONENTS
    geometry_msgs
    nav2d_navigator
    nav_msgs
    pluginlib
    roscpp
    visualization_msgs
    tf 
    std_msgs
)

catkin_package(LIBRARIES
    ExplorationPlugins
    CATKIN_DEPENDS
    roscpp
    tf
    pluginlib
    geometry_msgs
    nav_msgs
    visualization_msgs
    nav2d_navigator
    std_msgs 
)

include_directories(include/${PROJECT_NAME}/${catkin_INCLUDE_DIRS})

add_library(FrontierPlugins src/NearestBasedAllocation.cpp)
add_dependencies(FrontierPlugins ${catkin_EXPORTED_TARGETS})
target_link_libraries(FrontierPlugins ${catkin_LIBRARIES})

install(TARGETS FrontierPlugins  
    LIBRARY DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION})

install(FILES frontier.xml  
    DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION})

Can anyone please help me with the reason why I am unable to load these plugins? Thanks