I am very new to ArcGIS and I hope I have over-looked something obvious with this!
I have a set of polygons that have been loaded into ArcGIS Pro 10.3 without coordinate information. Unfortunately, it is not possible for me to get the co-ordinate information however I have been able to move the polygons to the correct position on a world map (it was quite easy because they line up with roads). However, I am unable now to 'share' this data online because I get the error: '20028 Data source has no spatial reference'.
Please does anybody know a way around this? Is there another way of sharing it or, ideally, can I get ArcGIS to work out the spatial references given the positions of the polygons on the map?