Blocked Subassembly Packet Files

Have you ever received a packet files from a source only to find that you get an error message when you try to use it in Civil 3D?
Well I did and got this error message:

So it pops up in Google searches it says:

Error: Unable to run the subassembly script.

The problem arose for me because Windows had blocked the packet file. This blocking carried over when I imported the subassembly into Civil 3D. To fix this go into Windows Explorer, Right click on the packet file, and choose Properties.

At the bottom of the General tab there might be a checkbox (or button) that indicates Unblock. Either check the check box (or press the button) and then press Ok. This will unblock the packet files.
Unfortunately, you are not done at this point. Two more steps need to be done.

• Open the packet file in Subassembly Composer and then save it. 
• Then delete the previously imported subassemblies from this folder: C:\ProgramData\Autodesk\C3D 2017\enu\Imported Tools\

Now when you import the packet file into Civil 3D again it should work correctly.