Publishing failed to complete. Unable to add feature service definition. Error code 400

Error Message

Attempts to publish a survey with ArcGIS Survey123 return the following error message:

Error:   
Publishing failed to complete. Unable to add feature service definition. Error code 400

Cause

The survey worksheet contains two or more questions with the same value. For example, in the survey worksheet, there are two unique rows with the exact same value in the 'name' column.

Solution or Workaround

To resolve this issue, ensure none of the fields contain the same value. Additionally, a folder in ArcGIS Online is created on the Content tab with files from the failed publication of the survey. This causes attempts to republish the survey to fail even after changing the values.

1. Log in to ArcGIS Online and navigate to Content > My Content.
2. On the left pane, under Folders, browse to the Survey-<Survey_Name> folder with the same name as the survey. This folder is created from the previous failed publishing attempt.
3. Hover over the folder. Click Edit Folder to modify the folder name, or Delete Folder to remove the folder.
4. In the survey XLSForm, open and check the survey worksheet to ensure there are no duplicate questions.
5. Republish the survey from ArcGIS Survey123 Connect.