Tech draw error

[Ukacor]

I made an assembly of 33 bodies from which I am compiling Tech Draw sheets (at the moment 3 pages) which I will attach to the documentation of a patent.
When I open the file in Report I read this:
DVP :: extractFaces - View -Can't make faces from projected edges
DVP :: extractFaces - View -Can't make faces from projected edges
DVP :: extractFaces - View001 -Can't make faces from projected edges
DVP :: extractFaces - View001 -Can't make faces from projected edges

Do you have any idea what could be due to it? It seems that I can't see faces but I see everything (it seems to me at least).

I cannot attach the file because it is too large.

Thank you.

OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.19424 (Git)
Build type: Release
Branch: master
Hash: 899854ac5d643e991a1006ed75aeff93baf3d224
Python version: 3.7.3
Qt version: 5.12.5
Coin version: 4.0.0a
OCC version: 7.3.0
Local: Italian / Italy (it_IT)

[wandererfan]

Do you have any idea what could be due to it? It seems that I can't see faces but I see everything (it seems to me at least).

This message means that the program could not make closed regions (Faces) from the edges in the projection. It may be that there is a gap somewhere, or that there are extra and/or overlapping edges that form false paths.

If you don't need to decorate faces (hatching for example) this message can be ignored. If you need to decorate faces, then we have to find the errors in the projection.

In an assembly of 22 bodies, there are almost certainly duplicate overlapping edges.

[Ukacor]

Wandererfan, you are very competent. Maybe this your answer perhaps gave me the cue to go and look for the errors you write about. Shurely there are overlapping edges created when i inserted threads in fasteners. I will check it! Any decoration requested in this assemply but for a correct learning i want correct it.


Many thanks.