I have imported numerous CSV files into ArcGIS before using the "Add XY Data" dialog box. Sometimes I run into a problem where I can select the table, but then the drop-down menus to specify the X, Y, and Z fields are blank, where they would usually display a column header like "Longitude" (see picture below).
I'm running into this problem now. The CSV table has a header row, but nothing shows up in the Add XY data dialog box field specification, so I cannot add the data to ArcGIS. I've also tried importing the table and displaying as XY data, but the problem persists. This has happened in ArcMap versions 10.2 and 10.3.
Any ideas why Arc can't find XY fields? Could special characters in the table create this problem?
Here's a sample of the data: