Please help! Your form cannot be deployed because it contains errors: Expecting value: line 2 column 1 (char 1)

I have some difficulties to deploy the survey questionnaire. Here is what it shows first when trying to deploy
your form cannot be deployed because it contains errors:

Expecting value: line 2 column 1 (char 1)

How can I fix that. I read all your comments but cannot find the bug .

Welcome to the community, @pierre2021! Would you mind validating your xlsform with this online validator? It should help you identify the syntax errors that is present within your xlsform.