These are only warnings: You use groups without a label (begin_group element). This might be intentional, if you do not want to show a group label and the grouping to the user.
See similar previous discussions in the forum (can be found with the search function, please), e.g. Error Loading Form - Failed to Fetch - #5 by wroos. And the ODK documentation Form Logic - ODK Docs.
(@Kal_Lam, might be helpful to add such a hint also to the Kobo Help Center article?)
