[Koha] Getting error after migrating data from Koha 3.10 to 16.11

[Server Room Thane]

Dear All,

We are getting some problem while migration of Koha 3.10.04.000
to 16.11.07.000.

I have took backup of Koha 3.10 using *mysqldump. *And after installation
of koha 16.11, restored dump. Upgraded Database Schema.  Everything goes OK.

But when I am trying to login using superadmin (Koha_library), each time I
am getting following error in *Staff client. *

*Error: You do not have permission to access this page.*
But after just refreshing staff clients login page, I am able to
login successfully.
And logs of intranet-error.log will get following lines.

[Sun May 14 11:49:24.256127 2017] [cgi:error] [pid 12639] [client
10.1.1.4:2745] AH01215: [Sun May 14 11:49:24 2017] mainpage.pl: Use of
uninitialized value in string eq at
/usr/share/koha/lib/Koha/Template/Plugin/Branches.pm line 68.:
/usr/share/koha/intranet/cgi-bin/mainpage.pl, referer:
http://10.1.1.28:8080/
[Sun May 14 11:50:54.540250 2017] [cgi:error] [pid 12654] [client
10.1.1.4:2755] AH01215: [Sun May 14 11:50:54 2017] mainpage.pl: Use of
uninitialized value $userid in string eq at /usr/share/koha/lib/C4/Auth.pm
line 2016.: /usr/share/koha/intranet/cgi-bin/mainpage.pl, referer:
http://10.1.1.28:8080/
[Sun May 14 11:50:54.540345 2017] [cgi:error] [pid 12654] [client
10.1.1.4:2755] AH01215: [Sun May 14 11:50:54 2017] mainpage.pl: Use of
uninitialized value $userid in string eq at /usr/share/koha/lib/C4/Auth.pm
line 2021.: /usr/share/koha/intranet/cgi-bin/mainpage.pl, referer:
http://10.1.1.28:8080/
[Sun May 14 11:51:18.208037 2017] [cgi:error] [pid 12660] [client
10.1.1.4:2760] AH01215: [Sun May 14 11:51:18 2017] mainpage.pl: Use of
uninitialized value $userid in string eq at /usr/share/koha/lib/C4/Auth.pm
line 2016.: /usr/share/koha/intranet/cgi-bin/mainpage.pl, referer:
http://10.1.1.28:8080/cgi-bin/koha/mainpage.pl?logout.x=1
[Sun May 14 11:51:18.208235 2017] [cgi:error] [pid 12660] [client
10.1.1.4:2760] AH01215: [Sun May 14 11:51:18 2017] mainpage.pl: Use of
uninitialized value $userid in string eq at /usr/share/koha/lib/C4/Auth.pm
line 2021.: /usr/share/koha/intranet/cgi-bin/mainpage.pl, referer:
http://10.1.1.28:8080/cgi-bin/koha/mainpage.pl?logout.x=1

In OPAC webpage I am getting following error.

Software error:
Can't call method "is_debarred" on an undefined value at
/usr/share/koha/opac/cgi-bin/opac/opac-user.pl line 93.

And logs of opac-error.log will get following lines.

[Sun May 14 11:59:06.862748 2017] [cgi:error] [pid 12699] [client
10.1.1.4:2858] AH01215: [Sun May 14 11:59:06 2017] opac-user.pl: Use of
uninitialized value $userid in string eq at /usr/share/koha/lib/C4/Auth.pm
line 2016.: /usr/share/koha/opac/cgi-bin/opac/opac-user.pl, referer:
http://10.1.1.28/cgi-bin/koha/opac-user.pl
[Sun May 14 11:59:06.863125 2017] [cgi:error] [pid 12699] [client
10.1.1.4:2858] AH01215: [Sun May 14 11:59:06 2017] opac-user.pl: Use of
uninitialized value $userid in string eq at /usr/share/koha/lib/C4/Auth.pm
line 2021.: /usr/share/koha/opac/cgi-bin/opac/opac-user.pl, referer:
http://10.1.1.28/cgi-bin/koha/opac-user.pl
[Sun May 14 11:59:07.301035 2017] [cgi:error] [pid 12699] [client
10.1.1.4:2858] AH01215: [Sun May 14 11:59:07 2017] opac-user.pl: Can't call
method "is_debarred" on an undefined value at
/usr/share/koha/opac/cgi-bin/opac/opac-user.pl line 93.:
/usr/share/koha/opac/cgi-bin/opac/opac-user.pl, referer:
http://10.1.1.28/cgi-bin/koha/opac-user.pl

*Koha 3.10's Superadmin's default username was "Kohaadmin". And Koha
16.11's default username is "Koha_library". is this creates problem*?

Kindly help me to resolve this issue.

Note : If I create new Patron, I am able to login to OPAC.

Thanks & Regards,
Sandeep Ulhalkar

(VPM's Server Room)