[Koha] {UNKNOWN}: DBI Exception: DBD::mysql::db do failed: Duplicate entry '0' for key 'PRIMARY'

[Michael Kuhn]

Hi

We have loaded our Koha 19.11 database into a new Koha 24.05 instance. 
When running "koha-upgrade-schema" the following error appears:

...
Upgrade to 19.12.00.017  [12:00:41]: Bug 21674 - Add unique key 
(parent_id, branchcode) to library_group
{UNKNOWN}: DBI Exception: DBD::mysql::db do failed: Duplicate entry '0' 
for key 'PRIMARY'  at /usr/share/perl5/DBIx/Class/Schema.pm line 1118.
	DBIx::Class::Schema::throw_exception(Koha::Schema=HASH(0x55a4b4a0dba8), 
"DBI Exception: DBD::mysql::db do failed: Duplicate entry '0' "...) 
called at /usr/share/perl5/DBIx/Class/Storage.pm line 113
	DBIx::Class::Storage::throw_exception(DBIx::Class::Storage::DBI::mysql=HASH(0x55a4b9ff1b70), "DBI Exception: DBD::mysql::db do failed: Duplicate entry '0' "...) called at /usr/share/perl5/DBIx/Class/Storage/DBI.pm line 1623
	DBIx::Class::Storage::DBI::__ANON__("DBD::mysql::db do failed: 
Duplicate entry '0' for key 'PRIMARY'", DBI::db=HASH(0x55a4ba7d2b38), 
undef) called at 
/usr/share/koha/intranet/cgi-bin/installer/data/mysql/updatedatabase.pl 
line 20736


Does anyone know how to solve this problem? At the moment I'm not even 
able to find out in which table the duplicate entry can be found...

Best wishes: Michael
-- 
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