Questionnaires rejected as duplicates when they are not/could not upload data

I ran into a few problems I need help with please:

First, one of the users of the questionnaire could not send his saved questionnaires. He kept getting the error:

“Error: NOT FOUND (404) at

as well as

“Error: Generic Exception: Unable to resolve host “”:No address associated with hostname”.

We asked him to check that the URL in the server was correct (and to retry writing it), that the date and time were correct, and that he had a strong internet connection. After all of these did not work, we asked him to send us the files manually in a zip file over email.

Now, when I am trying to upload the questionnaires manually from the zip file he sent us using the bulk-submission-form page, I encounter a new error that I think says the forms are duplicates and have already been uploaded :

{“message”: “Submission complete. Out of 37 survey instances, 0 were imported, (37 were rejected as duplicates, missing forms, etc.)”, “errors”: "37 [‘Entretien individuel REDD_2019-06-20_13-08-55.xml => No XForm matches the given query.’

However, I know that these forms have not yet been uploaded as I do not have their data inside the project page.

Can someone please explain to me why the user couldn’t originally send the data and why now kobo is saying the questionnaires are duplicates even if I don’t have access to them on the project databse???

Thanks very much for any help!