Using the Label tool, from the Drawing toolbar, to label features for a layer that has a join (Layer Properties Joins & Relates tab) will crash ArcMap.
This will occur even if you don't use a field from the joined table as the label field.
The Label tool is unable to work with layers that have join enabled.
Solution or Workaround
This was fixed in ArcGIS Version 8.1.2.
- If you are not labeling a joined field:
1. Copy the layer.
2. Remove the join.
3. Label features from this layer instead.
- If you are labeling a joined field:
1. Export the layer to a shapefile (including the joined fields).
2. Add this shapefile as a layer and label it.
3. If it makes sense, convert the labels to annotation and store them in your map. This will allow you to remove the layer that was based on the shapefile.