[Koha] Getting errors while running process_message_queue.pl after KOHA upgradation

[Nirakar Mishra]

Sir/Madam,

I have recently upgraded KOHA from version 18.05.03 to 20.05, also upgraded
the OS from Ubuntu 18.04 LTS to 20.04 LTS recently. While using the KOHA
version 18.05, the process_message_queue.pl was running fine and the
circulation transaction notices were sending perfectly using the cronjobs.
But after upgrading, all the things are working fine except the notices. I
am getting the following errors and still couldn't find the solution. I am
using Postfix Email server which is also working fine. The settings I had
used in the KOHA version 18.05 are kept same. But I am getting the
following errors and also notices are not being sent.

*(1) For running the Cronjob from root: koha-foreach --chdir --enabled
--email /usr/share/koha/bin/cronjobs/process_message_queue.pl
<http://process_message_queue.pl>*

Use of uninitialized value $_ in concatenation (.) or string at
/usr/share/perl5/Mail/Sendmail.pm line 216.
Use of uninitialized value $_ in pattern match (m//) at
/usr/share/perl5/Mail/Sendmail.pm line 219.
Use of uninitialized value $_ in concatenation (.) or string at
/usr/share/perl5/Mail/Sendmail.pm line 402.
Connection error from localhost on port 25 ()
 at /usr/share/koha/bin/cronjobs/process_message_queue.pl line 92.

*(2) While running this as library-koha user: perl
/usr/share/koha/bin/cronjobs/process_message_queue.pl
<http://process_message_queue.pl>*

unable to locate Koha configuration file koha-conf.xml at
/usr/share/koha/lib/C4/Context.pm line 245.
Use of uninitialized value in concatenation (.) or string at
/usr/share/koha/lib/C4/Templates.pm line 154.
unable to locate Koha configuration file koha-conf.xml at
/usr/share/koha/lib/C4/Context.pm line 245.
unable to locate Koha configuration file koha-conf.xml at
/usr/share/koha/lib/C4/Context.pm line 245.
Use of uninitialized value in concatenation (.) or string at
/usr/share/koha/lib/C4/Auth_with_cas.pm line 42.
unable to locate Koha configuration file koha-conf.xml at
/usr/share/koha/lib/C4/Context.pm line 245.
Use of uninitialized value $INC[-1] in string eq at
/usr/share/koha/lib/Koha/Plugins.pm line 36.
Use of uninitialized value in require at (eval 1477) line 1.
Use of uninitialized value $_ in string ne at
/usr/share/perl5/Net/DNS/RR.pm line 39.
Use of uninitialized value in require at (eval 1484) line 1.
Use of uninitialized value in require at (eval 1486) line 1.
unable to locate Koha configuration file koha-conf.xml at
/usr/share/koha/lib/C4/Context.pm line 245.
unable to locate Koha configuration file koha-conf.xml at
/usr/share/koha/lib/C4/Context.pm line 245.
Can't call method "config" on unblessed reference at
/usr/share/koha/lib/Koha/Database.pm line 56.

Request your help to resolve the issue.

Thank you in advance.

Regards,
Nirakar Mishra
Bhubaneswar, India