I believe that there is a problem with the membership plugin. it clashes with other plugin like WPdatatables. the wordpress programmer I engaged mentioned the following probable cause:
1. all Membership 2 Pro scripts on all wp-admin pages
2. how to dequeue it when i am not on membership admin page (is there any other solutions that will only load the scripts only on membership 2 pages instead of the wp-admin pages)
3. It seems that One of the files that are causing conflict is select2.js library.
Your kind assistance on the above is greatly appreciated .