[Koha] There is no notice template with code ACQORDER defined

Hi Using Koha 18.11.01 on Debian GNU/Linux 9 we get the following error message, when clicking "E-mail order" in Koha menu "Acquisitions" in the basket of a vendor: There is no notice template with code ACQORDER defined. But actually the template "ACQORDER" is defined in Koha menu "Tools > Notices & slips" (it is a standard template anyway). It can also be found in table "letter". Does anyone know what is the problem here, or is this maybe a bug? Best wishes: Michael -- Geschäftsführer · Diplombibliothekar BBS, Informatiker eidg. Fachausweis Admin Kuhn GmbH · Pappelstrasse 20 · 4123 Allschwil · Schweiz T 0041 (0)61 261 55 61 · E mik@adminkuhn.ch · W www.adminkuhn.ch