The name of the field is invalid. Valid names may contain letters, numbers, or underscores

Error Message

Note:
This article pertains to ArcGIS versions 8.x only. Later versions of ArcGIS may contain different functionality, as well as different names and locations for menus, commands and geoprocessing tools.

When adding a delimited text file to ArcMap, the selected item could not be added to the map, and the following error is returned:

The name of the field is invalid. Valid names may contain letters, numbers, or underscores.

Cause

One or more of the field names contain characters that are invalid for delimited text file data. Letters, numbers and underscores are the only valid characters for delimited text file field names. Affected fields can include table and column names, and layer names.

Solution or Workaround

1. Open the delimited text file in a text editor.
2. Identify the field name specified in the error message.

Note:
The word inside the square brackets at the end of the message specifies the offending field name.

3. Replace the invalid characters with letters, numbers or underscore characters in the field name.

For example: 

A field named: x-coord can be changed to x_coord 
A field named: roads# can be changed to roads_

4. Repeat step 3 for all other fields in the text file.