Hi  I am trying to upgrade koha from Koha18.05.04.000 to Koha21.05. When I upgrade the schema, I receive the following error message
> ISBN_RANGE_MESSAGE is set to [] but that file does not exist!
> Trying to use the default locations
> at /usr/share/perl5/Business/ISBN.pm line 87.
> Can't use string ("- id: 165
> selector: #coverflo"...) as an ARRAY ref while "strict refs" in use at
> /var/lib/koha/library/plugins/Koha/Plugin/Com/ByWaterSolutions/CoverFlow.pm
> line 377.
Thanks in advance for your help.