Can you please share a screenshot from the submission detail page in Central? If it has sensitive info you can black it out or send it to me privately.
@AHidalgo wrote me some more details privately and as I understand it, media attachments for submissions that were collected with Collect v2025.2.1 can't successfully be updated by Enketo but submissions made from Collect v2025.3.1 can. I don't currently have any idea why and haven't been able to reproduce yet.
@AHidalgo could you please try editing with Web Forms instead? For that form, go to Settings and opt into ODK Web Forms. Then edit the submission and see if you are able to make the edit.
Thank you for following up! We've been looking into the issue, and while trying to reproduce the Web Forms error: Cannot read properties of undefined (reading 'blob'), using various file types and Collect versions, we haven't had any luck triggering it on our end so far.
During our investigation, we did find and fix a related bug regarding attachments when updating older form submissions. This fix will be available in the next Central release, but we aren't certain it's the exact issue you are running into.
To help us track down exactly what is happening, could you send me a Direct Message (DM) here on the forum with a few more details?
Your exact Central version
Your form definition
The submission XML for the record you are trying to edit
Sending these in a private message ensures your form and submission data remain secure.