[Koha] Koha after update 21.05 Error with new record.

[Tadas G]

Hello, after update koha from 20.05 to 21.05 version then a problem
appeared.
New record from Z39.50/SRU is working and save normal.
But add new record without Z39 search write error after saving.

After save occurred error:
Bibliographic record not found.

Log:
[Fri Aug 06 13:26:01.655638 2021] [cgi:error] [pid 94489] [client
x.x.x.x:x] AH01215: Use of uninitialized value in concatenation (.) or
string at /usr/share/koha/intranet/cgi-bin/cataloguing/addbiblio.pl line
262, <DATA> line 755.: /usr/share/koha/intranet/cgi-bin/cataloguing/
addbiblio.pl, referer: xxx/cgi-bin/koha/cataloguing/addbooks.pl
[Fri Aug 06 13:26:01.655783 2021] [cgi:error] [pid 94489] [client
x.x.x.x:x] AH01215: Use of uninitialized value in concatenation (.) or
string at /usr/share/koha/intranet/cgi-bin/cataloguing/addbiblio.pl line
262, <DATA> line 755.: /usr/share/koha/intranet/cgi-bin/cataloguing/
addbiblio.pl, referer: xxx/cgi-bin/koha/cataloguing/addbooks.pl
[Fri Aug 06 13:26:14.776592 2021] [cgi:error] [pid 94502] [client
x.x.x.x:x] AH01215: Use of uninitialized value in concatenation (.) or
string at /usr/share/koha/intranet/cgi-bin/cataloguing/addbiblio.pl line
262, <DATA> line 755.: /usr/share/koha/intranet/cgi-bin/cataloguing/
addbiblio.pl, referer: xxx/cgi-bin/koha/cataloguing/
addbiblio.pl?frameworkcode=PROJ
[Fri Aug 06 13:26:14.776746 2021] [cgi:error] [pid 94502] [client
x.x.x.x:x] AH01215: Use of uninitialized value in concatenation (.) or
string at /usr/share/koha/intranet/cgi-bin/cataloguing/addbiblio.pl line
262, <DATA> line 755.: /usr/share/koha/intranet/cgi-bin/cataloguing/
addbiblio.pl, referer: xxx/cgi-bin/koha/cataloguing/
addbiblio.pl?frameworkcode=PROJ
[Fri Aug 06 13:26:14.798403 2021] [cgi:error] [pid 94502] [client
x.x.x.x:x] AH01215: substr outside of string at
/usr/share/perl5/MARC/File/XML.pm line 563.:
/usr/share/koha/intranet/cgi-bin/cataloguing/addbiblio.pl, referer:
http://xxx/cgi-bin/koha/cataloguing/addbiblio.pl?frameworkcode=PROJ
[Fri Aug 06 13:26:14.798489 2021] [cgi:error] [pid 94502] [client
x.x.x.x:x] AH01215: Use of uninitialized value $enc in string eq at
/usr/share/perl5/MARC/File/XML.pm line 565.:
/usr/share/koha/intranet/cgi-bin/cataloguing/addbiblio.pl, referer:
http://xxx/cgi-bin/koha/cataloguing/addbiblio.pl?frameworkcode=PROJ
[Fri Aug 06 13:26:14.798566 2021] [cgi:error] [pid 94502] [client
x.x.x.x:x] AH01215: Use of uninitialized value $enc in string eq at
/usr/share/perl5/MARC/File/XML.pm line 565.:
/usr/share/koha/intranet/cgi-bin/cataloguing/addbiblio.pl, referer:
http://xxx/cgi-bin/koha/cataloguing/addbiblio.pl?frameworkcode=PROJ
[Fri Aug 06 13:26:14.798642 2021] [cgi:error] [pid 94502] [client
x.x.x.x:x] AH01215: Use of uninitialized value $enc in string eq at
/usr/share/perl5/MARC/File/XML.pm line 567.:
/usr/share/koha/intranet/cgi-bin/cataloguing/addbiblio.pl, referer:
http://xxx/cgi-bin/koha/cataloguing/addbiblio.pl?frameworkcode=PROJ
[Fri Aug 06 13:26:14.798733 2021] [cgi:error] [pid 94502] [client
x.x.x.x:x] AH01215: Use of uninitialized value $enc in concatenation (.) or
string at /usr/share/perl5/MARC/File/XML.pm line 570.:
/usr/share/koha/intranet/cgi-bin/cataloguing/addbiblio.pl, referer:
http://xxx/cgi-bin/koha/cataloguing/addbiblio.pl?frameworkcode=PROJ
[Fri Aug 06 13:26:14.800587 2021] [cgi:error] [pid 94502] [client
x.x.x.x:x] AH01215: {UNKNOWN}: Unsupported UNIMARC character encoding []
for XML output for UNIMARC; 100$a -> gfbgfbgfb at
/usr/share/perl5/MARC/File/XML.pm line 570. at
/usr/share/koha/lib/C4/Biblio.pm line 297:
/usr/share/koha/intranet/cgi-bin/cataloguing/addbiblio.pl, referer:
http://xxx/cgi-bin/koha/cataloguing/addbiblio.pl?frameworkcode=PROJ
[Fri Aug 06 13:26:14.800713 2021] [cgi:error] [pid 94502] [client
x.x.x.x:x] AH01215: Use of uninitialized value $biblionumber in
concatenation (.) or string at /usr/share/koha/intranet/cgi-bin/cataloguing/
addbiblio.pl line 873.: /usr/share/koha/intranet/cgi-bin/cataloguing/
addbiblio.pl, referer:
http://xxx/cgi-bin/koha/cataloguing/addbiblio.pl?frameworkcode=PROJ

Maybe for someone it happened after the update?