Hatching Issues
Qnologi's video is one good way of saving custom hatch patterns. The other way, and the one I suspect you did, is to add the custom hatch pattern to acad.pat file (located by default in the C:\Users\<username>\AppData\Roaming\Autodesk\C3D 2016\enu\Support folder). Notice the versioning (mine is for Civil 3D 2016). I'll talk about that in a sec.
In that file you'll find this:
Notice the that this has the word "migrate" in that highlighted statement. This custom hatch file will migrate over to the next version if, and only if, I use the migrate tools. So when I install Civil 3D 2017 if I don't migrate this file then I will not have the custom hatch pattern. Also,(now back to the versioning topic) if I should uninstall 2016 this folder where the hatch pattern is saved (for 2016) will be removed from my system. So your options are to migrate automatically using the migrate tool or migrate manually by saving a copy of this file and replacing it with the one that ships with the next version software.
My suspicion is that you had this file set up correctly in your previous software but didn't migrate it. My hopes are that you still have your previous software on your system so you can copy the file out for safe keeping and manually replace the current file for your newer version software.
However, if you removed the previous version software you are now at risk of losing that custom hatch pattern. Do you know where you got this custom pattern? Can you get it again? Do you have a drawing with the hatch pattern in it? If so, can we see it. I think I have an idea on how to possibly fix this but need to test first.
So does each hatch pattern have it's own file name? If so then Qnologi's method works best for you. Do you see your hatch pattern in that 2013 folder? The file extension will be .pat. If so, then yes, copy them to your support folder in 2016. If not, then we're stuck and you can try stealing it from an existing drawing and add it to your tool palette as so:
However, we cannot test this without a drawing.
I feared this:
But look what I found at near the bottom of this page: http://www.archblocks.com/archblocks-cad-blocks-and-products-previews/autocad-hatch-patterns
I also found the same hatch pattern at this site: http://www.simplecad.com/autocad-hatch-patterns.htm.
Now I've never used them before so proceed with caution. It might be worth a try.
