Looking at your form, I observed that you had many questions and choices in your survey project. I tried to upload your xlsform to my user account, and it took a lot of time. Then, when trying to open the survey project through Enketo, I saw the same error message with my user account too. I then tried using the KoBoCollect android app, and then I was able to upload the survey project to my android app. Hence, at this point, I would advise you using the KoBoCollect android app, which should solve your issue.
Maybe this post discussed previously should also explain to you what happens if you have a large survey project (and try to open it through Enketo):
