Windchill customization related to table builder

I am new to windchill customization need help to fix my issue related to table building activity 

i have created an customaction.xml as below 

   <objecttype name="tab" resourceBundle="custaction.CustActionRB">
   <action name="Association">
   <component name="custaction.DemoTableBuilder" />
   </action>
   </objecttype>
   

i am able to find the action button but when i am trying to load the page i am getting below error 

my code seems to be good 

Kindly help me to fix the issue