There are likely multiple things happening here. To Replicate 1. Ensure the Advanced Editor is enabled. 2. Edit a record or two with the Advanced Editor to ensure the cookie is saved to the browser to open the advanced editor when editing and not the basic editor. 3. Ensure the system preference EasyAnalyticalRecords is set to 'Don't show'. 4. Ensure the system preference UseControlNumber is set to 'Use' 5. Find a "parent" record and click on New -> New child record. 6. The advanced editor opens - no pre-filled 773 tag 7. Switch to the basic editor. 8. See that the 773 tag is not filled out. Adding a new child record fails. 1. Now edit a different existing record. The advanced editor opens. 2. Switch to the basic editor. Edit and save. 3. Edit the record again and the advanced editor opens. In the past, Koha remembered which editor style was opened last. Because it is not doing that now, it seems impossible to add a child record with the advanced editor enabled. This is perhaps a separate bug. Previous behavior was the last used editor was the one opened. Now it appears that if the Advanced editor is enabled, that is the one opened by default. Next: 1. Disable the Advanced Editor in the system preferences. 2. Find a record to edit. 3. New -> New child record See that the basic editor opens and the 773 tag is auto-populated. Adding a child record works. 4. Enable the Advanced Editor. 5. Find a record to edit. 6. New -> New child record See that the Advanced Editor opens again and can't add a child record.
*** This bug has been marked as a duplicate of bug 30052 ***