Custom Field Created but A PHP Error was encountered


I am getting the error below after I have added a custom field:

A PHP Error was encountered

Severity: Notice

Message: Undefined index: jb_client_custom

Filename: views/index.php

Line Number: 36


File: /home/hubnzworldtours/public_html/jb/application/modules/custom_fields/views/index.php
Line: 36
Function: _error_handler

File: /home/hubnzworldtours/public_html/jb/application/third_party/MX/Loader.php
Line: 464
Function: include

File: /home/hubnzworldtours/public_html/jb/application/third_party/MX/Loader.php
Line: 416
Function: _ci_load

File: /home/hubnzworldtours/public_html/jb/application/modules/layout/controllers/Layout.php
Line: 40
Function: view

File: /home/hubnzworldtours/public_html/jb/application/modules/custom_fields/controllers/Custom_fields.php
Line: 40
Function: buffer

File: /home/hubnzworldtours/public_html/jb/index.php
Line: 325
Function: require_once

Despite the error above, initially, the custom field had appeared during the entry of data during invoice creation, but it is not showing the dropdown menu of custom field.

Can someone be kind to suggest the solution?

Thank you in advance.