You placed a Bubble Callout in a detail, and the callout is appearing as only a blank circle. If you place a Bubble Callout Schedule, the callouts will also appear blank (see image to the right).
If you use the Explode command to explode one of the callout blocks, you should still see the numbers 00, which indicates that the callout attribute is still present.
This issue is an AutoCAD bug caused by placing an attribute item after previously deleting and purging it from the drawing without having closed and reopened AutoCAD. If you create a text style and block immediately after purging them both, the attribute for that block will come in blank.
1. Save any changes to the drawing. Close AutoCAD and reopen the drawing.
2. Try to place a Bubble Callout again.
3. Place a text object using the same Detail Title font (you can use our Text tool to place the text).
4. Place a Bubble Callout again. You should now see the number in both the callout and the schedule.