ArcCatalog

[ChrisSlinko]

I've created a feature class from XYZ points that were in an excel spreadsheet.  I've exported them to a feature dataset.  Next I wanted make some edits to the Feature Class Properites/Fields tab.  I would like to add more field names, and now it won't let me add/edit any of the field names. Does anyone have any suggestions?

[JakeSkinner]

This is most likely due to a schema lock.  Is the data open in ArcMap? 

If so, try closing ArcMap, or in ArcMap right-click on the layer > Open Attribute Table > click the drop down > Add Field.