We have a feature class that was converted from a shapefile from a 3rd party software. The software can only convert all the data into String type format. In the ArcMap days, our analyst will painstakingly add needed numeric fields before creating a proportional symbol for his report. When we try to use arcade with proportional symbol we immediately run into a problem in ArcGIS Pro (v 2.1.2). When we click on the layer in the TOC > appearance > Symbology > Symbolize by Quantities, we notice this warning immediately - Layer does not contain any field types that can be used to quantify using proportional symbols
Even if closing the warning message, the Arcade option remains unavailable.
Interestingly, if symbology is changed to Unique Values, there is no warning and I can pick the field to apply Arcade.