Extensions often have dependencies. If you manually copied only one folder, the installation might fail. Always copy the full "Repository" structure provided in the offline installer download.
Under the section, locate the Offline Installation option. Check the box for Use a local installation service .
If you can’t simply hit "update" within the software, here is the step-by-step guide to managing an Altium extension offline installation. Phase 1: Preparing the Offline Installation Files altium extension offline install
Click the (download icon) next to the specific extension you need (e.g., Draftsman or KiCad Importer ).
Once the path is set, Altium will "see" the extensions available in that folder as if they were live on the web. Stay in the tab. Click on the Purchased or Installed sub-tab. Extensions often have dependencies
In the path field, browse to the folder on your USB or network drive where you stored the offline repository files. Phase 3: Installing the Extension
Click the button (the gear icon) in the top right corner. Under the section, locate the Offline Installation option
You should now see a list of extensions available from your local source.