I recently upgraded our Koha from 18.11 to 19.05, and the following problem showed up: when attempting to add a new item for a bib record from an imported MARC record, the new item page briefly shows up, then closes the tab. I have observed this in Firefox 69.0.1 on Linux Mint as well as Pale Moon. Here's how to get this to happen: Use "Stage MARC for import" and "Staged MARC management" to import a MARC record. Make sure to tell Koha NOT to process item data. Once the record has been imported and the "Staged MARC management" page is showing the table containing the record summary, click on the record number in the rightmost column of the table. This should open a new tab showing the catalog details for the new bib record. Select "New item" from the "New" button at the top of the page. The new item form will show for a fraction of a second, but then the tab will close. I'm fairly sure this behavior didn't occur in 18.11.
Hi Mark, I think this is a duplicate to bug 23680 that has just been pushed to master and should be checked by Release Maintainers for backporting soon. *** This bug has been marked as a duplicate of bug 23680 ***