Server error (500) on Deployment of survey

Hi,
I have done a survey on Kobo and runs well but when I try deploying it,I get the below attached error. What could be the issue? Server error (500)

@mnelson, have you validated your XLSForm through this online validator? The online validator should help you identify syntax issues if any that are affecting the form deployment.

This post discussed previously should help you use the online validator.