Using ArcMap 10.5.1
I'm new to ArcMap and I imported a table into my map and then displayed the XY data. I am using proportional symbology to represent the error within the data and it worked smoothly for every data set (I have error represented in a field with a number indicating meters) but two of my sets (whose source data is identically formatted to all of the others) read my error field as a text string. It is literally a number with no text in the field (save the field header) and when I go to change it the box is grayed out, indicating it can't be changed. Is this a new user error on my part, or something others have run into?
Thank you for your help.