I configured all my extensions,
when I go to Extension configuration it list no extensions numbers only the icon to delete the entries,
It looks like the extension file is corrupted.
Because of the file corruption you will need to blank the file and add/import the extensions again.
Please see forum post: How do I import extensions from a file into TNG?
After a power out, that no extensions displayed under extension configuration.
Power failure can also corrupt the tngext.dat and tngdept.dat files.
Follow the steps : How do I import extensions from a file into TNG?