Hi there,
Yes this can sometimes happen because of connectivity issues. You can test this by terminating your locally running app in Studio Pro and trying to navigate through your app (no connectivity -> throws this error)
Other times, this can happen when you don't have error handling within your application (e.g., in microflows). Mendix provides resources on error handling in the Academy and documentation
This will allow you to provide custom error messages and logic for instances when internet connectivity isn't the issue.
Hope this helps,
Liam