Unlike standard Civil 3D subassemblies built with .NET or VBA code, PKT files are:
Civil 3D throws an error stating the file cannot be read. Civil 3d Subassembly Pkt- Download
Right-click on any existing tab or the blank sidebar area of the Tool Palette window. Select from the context menu. Unlike standard Civil 3D subassemblies built with
.pkt files made in newer versions of Subassembly Composer may not open in older Civil 3D versions. Dependency: Civil 3d Subassembly Pkt- Download
This happens when Civil 3D loses the path to the original PKT file location. This often occurs if you move, rename, or delete the PKT file from your hard drive after importing it. To resolve this, re-import the file using the correct path and rebuild your corridor. Issues with Subassembly Scaling or Units