https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=42277 --- Comment #4 from Brendan Lawlor <blawlor@clamsnet.org> --- This works and makes sense to use optional chaining when a property or a function might not exist. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/... Testing notes: I also tested closing and opening a subscription and managed to get two slightly different errors. It's pretty cool how the dev tools link to subscription-detail.pl shows you the exact line where the error comes from, even though the line numbers are different. jquery-3.6.0.min_25.1200046.js:2 jQuery.Deferred exception: Cannot read properties of undefined (reading 'DataTable') TypeError: Cannot read properties of undefined (reading 'DataTable') at HTMLDocument.<anonymous> (http://localhost:8081/cgi-bin/koha/serials/subscription-detail.pl:2191:34) jquery-3.6.0.min_25.1200046.js:2 Uncaught TypeError: Cannot read properties of undefined (reading 'DataTable') at HTMLDocument.<anonymous> (subscription-detail.pl:2191:34) Nice work! Passing QA. -- You are receiving this mail because: You are the assignee for the bug. You are watching all bug changes.