Hello - We use collaboration to push our ArcEnterprise 10.6.1 portal hosted layers to our ArcGIS Online organization and in turn make those layers available to Open Data.
I just noticed in the last week or so that once you are on the Overview tab on your Open Data site, and click an attribute that has charting and/or map visualization enabled (not sure how Open Data even selects which attributes can be charted and/or map visualized) AND a count error is returned:
That in turn is throwing an SEVERE error category (that I get to see in ArcGIS Monitor) for the given hosted feature layer that resides in our Portal:
The submitted field 'comments_COUNT' is not available in the layer '0' of the service 'wFireDeptConnection'.
and so on every time someone anywhere wants to visualize or chart one of the variables that supports that capability.