update failed

[HannesZiegler3]

While using the Collector app on iPad/Android phone I get an error message that reads "Update Failed The update could not be sent". I have add, edit, and delete enabled and sync is enabled but grey (cannot be toggled off). I am not an administrator. The feature service is hosted on ArcGIS Online. Has anyone else had this issue, and what is causing it? 

Thank you

[HannesZiegler3]

We have found the cause of the problem. Make sure your data does not contain m- or z-values (not m- or z-aware). How To: Remove Z- and/or M-values from a feature class. AGOL maps can work with them, but collector cannot.