2816150 - *ERROR: The new SAP tools in <path>/SUM/abap/exe cannot connect to your database

• While performing an upgrade using the Software Update Manager (SUM), an error occurs in the phase DBCONNCHK_INI
• The error message is similar to :

*ERROR:* The new SAP tools  Showing only entries of type error...
=========== Action PREP_INPUT_CHECK/DBCONNCHK_INI, Type error: Database connect failed ===========

*ERROR:* The new SAP tools in /usr/sap/<SID>/SUM/abap/exe cannot connect to your
database.

Possible reasons are:

 * Environment variables are not properly set for the version of the
 database client which is used by the new tools.
 * Required database libraries are not accessible or cannot be found neither
 through a compiled-in path nor through explicit search via the shared
 library path.
 * Auxiliary files such as language files etc. are not compatible with this
 version of the database client.
Please check database / OS specific notes referenced in the manual for more
help.
The log file DBCONNCHK.LOG contains more details about the failure.

Converting 3 entries from 'CHECKS.LOG'

>> Current module status: continue with phase PREP_INPUT_CHECK/DBQUERY_INIT
Converting 3 entries from 'CHECKS.LOG'
>> Waiting for request handler...

Prepare module , KBA , BC-UPG-TLS-TLA , Upgrade tools for ABAP , Problem