I am not able to visualize an xlsform cause I think it is too heavy

[Kal_Lam]

@valbo_0906, this post discussed previously should help you learn more about what happens when you have too long questions in your survey project:

Loading Error ,Unexpected token < in JSON at position 0

@adminpro, yes it affects the loading when you have a long list of questions or choices in your survey project. Please be informed that the web server only allows each request to take 120 seconds. And if a form is not able to load even within this 120 seconds your forms do not get deployed/loaded. You could thus solve this by either trying to collect your data through Collect android app or build your survey project using an external select (if you have a long list of choices).