Cache spatial reference error when exporting web map

[cr3]

This is my first time trying to share a web map.  All of my layers are in the correct projection, NAD 1983 UTM Zone 4N, including my basemap which I made from custom.  When I try to export it, I get the following error: "00079 Cache spatial reference does not match map/dataset/ layer spatial reference" 

How do I change the cache spatial reference?  

Thank you 

[StephanieM1]

Could you try saving your project, closing it, and trying to publish again?

If not, are you able to publish the custom basemap as a layer to ArcGIS Online?

https://pro.arcgis.com/en/pro-app/latest/help/sharing/analyzer-error-messages/00079-cache-spatial-re...