BUG #16116: function lpad(integer, integer, integer) does not exist

The following bug has been logged on the website:

Bug reference:      16116
Logged by:          vijay ingle
Email address:      vjingle143@gmail.com
PostgreSQL version: 11.4
Operating system:   Linux
Description:

Hi,
We are getting an error function lpad does not exists.
I had created one project on community version (PostgreSQL 11.4 on
x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 (Red Hat
4.8.5-36), 64-bit) which is successfully running , all procedures and
functions run successfully. 
Now i had created one more project having same version on same server also
and migrated all source code of my existing project including (tables, seq,
index, procedure, functions) means created replica of existing project but
whenever i tired to run my procedure then getting an error.