[Koha] Internal server error with ISBD detail and making a hold on OPAC

[Paul]

I’m recently started to get internal server errors when looking at ISBD
detail and making a hold when in the OPAC.

We’re using Koha 19.11.22.000 on Debian 9.

I’ve seen a similar problem reported as bug 22735: Resolve internal server
error on missing item type but that was on 18.05 and presumably fixed back
then.

Can anyone offer any fixes please?

Paul Leman

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Paul Leman