Issue
"... I'm back and was wondering if anyone else has had this issue. I'm working in ASE and am getting this after doing several commands. For example I was defining links for a grading design, then I would get an error message. I tried to save but am unable.
Specify grade path [Linear/Curved]<L>:
Enter percent grade from 'PARENT' to 'CHILD'<-2.1229%>: .5
; error: bad argument type: numberp: nil
Command:
_QSAVE ; error: non-serializable lisp data: #<%catch-all-apply-error%>

I am unable to save the drawing. I tried saving using saveas and tried saving to another drive. Can you please tell me if this is an autocad, windows, or ASE issue? I can get out of autocad, reboot the computer and the same issue returns. I am using C3D 2018 with the latest ASE 2017, and Windows 7 Pro…"
This is caused by a known defect in ASE.
The AutoCAD Message and error condition at the command line occur whenever Flow Labels have been passively generated as a result of the vertical design "Productivity" setting being enabled. This feature creates Flow Labels automatically when Constraints or Connections are created. This problem occurs in the 2017 version of ASE.
Solution
Open the vertical design drawing
(Ribbon) Select: [vrtCtrl] -> Flow Labels -> Preferences
In the FLow Labels Preferences dialog, DISABLE "Productivity"
Run ASE "Selective Audit..."
Close the dialog
Save the drawing
Re-start Civil 3D

Thanks for sharing that information!
But I figured out the issue. When a flow label is present and you delete a marker, the program deletes the slope text and not the arrow. This causes the same message as the auto-label audit. I had leftover arrows under new ones that I added after the auto-label didn't work.
Nope. I saved/closed multiple times. This is what i see when opening and when a initializing and when auditing. (see below)
That sounds like cached memory still present in the drawing.
Try saving the drawing then restarting Civil 3D.
Sorry, After I turned it off and did the Selective Audit, I was able to save. But every time I run the Selective Audit it keeps finding/fixing the corrupt flow labels. So I don't think it's really cleaning the drawing.
Even after disabling the setting?
Got the same issue