Problem: XY event themes created from text files are unable to be selected
When creating an XY event theme from a text file, for example, CSV files, the ability to select features is disabled and therefore cannot support selections.
The text file does not have a field ArcGIS can use as an ObjectID. The ObjectID identifies each feature with a unique value.
Solution or Workaround
ArcGIS can select and edit features in an XY event theme only if the underlying data type supports an ObjectID field. Convert the text file to a format, such as DB 4, that supports an ObjectID field.