"Warning: An error occured during save" arises when saving a drawing which contains a style which was created with a layer from another "layer source" drawing.

1.  File new from _AutoCAD Civil 3D (Imperial) NCS Extended.dwt (drawing2.dwg) 2.  File new from acad.dwt (drawing3.dwg) 3.  Under toolspace/settings for drawing3.dwg, right click on General-Label Styles-Line and select New.
4.  General tab, left click on the box next to Layer that currently contains 0, then click on the ... to the right.
5.  Left click on Drawing3.dwg under Layer source at the top left of the Layer Selection dialog and select Drawing2.dwg.
6.  Select C-ANNO then OK and OK and save the drawing as temp.dwg.

This results in an AUTOCAD Message box with this text:

Warning:  An error occured during save.
We recommend that you run RECOVER on the drawing.

In Civil 3D, several of the inquiry commands under the map menu don't work:

Map-Inquiry-Line and Arc Information
Map-Inquiry-Angle Information
Map-Inquiry-Continuous Distance
Map-Inquiry-Add Distances
Map-Inquiry-List Slope

1. Create a Curve Label Style with the following settings:
   • Allow Curved Text = true
   • Border Visibility = true
   • Background Mask = true
2. Before you OK the label style, you'll notice that the border is not going to be correct.
3. Draw an arc.
4. Place the curve label style on arc and check the location of the border and the background mask.

The background mask matches the border, but neither matches the text.  It works fine if you don't use "Allow Curved Text".

1. Create a new drawing from the acad.dwt drawing template.
2. Set the annotation scale to 1"=40'.
   
3. Place some points manually.
4. Drag the labels of the points so that the leader arrowhead is visible.
   
5. Create a new Point Label Style with the dragged state arrowhead set to origin indicator 2.
   
6. Change the Point Label Style of the manually placed points to the new Point Label style.
7. Save the drawing (Points-1.dwg).
8. Create a second drawing from the acad.dwt drawing template.
9. Save the drawing as (Sheet-1.dwg).
   
10. Set the annotation scale to 1" = 40'.
    
11. Overlay the first drawing (Points-1.dwg) into the second drawing.
    
12. Zoom extents and view the arrowheads.