Fixing missing objects and library parts in hotlink modules (.mods) and host file

Issue description

You place a module via File > External Content > Place Hotlink, but in the host file, the hotlinked model shows missing objects, such as doors and windows that appear as dots or are not visible at all on the floor plan and in 3D.

In the host file's Library Manager, you see the warning Missing Library Parts, and the listed hotlink source libraries differ from the libraries loaded in the host file.

When you open the hotlink source project on its own, all components display correctly, but once hotlinked into the host, elements no longer show correctly.

Solution

Placing a hotlink module does not import any linked library parts from the source file into the host. This behavior causes missing elements when host and hotlink files use inconsistent library setups — for example, mixing Global and Monolith libraries, using different language versions of the same library, loading libraries from different Archicad versions instead of migrating project libraries, or omitting custom office libraries from the host.

To resolve missing doors, windows, and other objects, align the library setups across host and hotlink files, and regularly review library warnings in Library Manager following the checklist below.

General checklist for library management between host files and hotlinks

1. Open Library Manager in the host file via File > Libraries and Objects > Library Manager
2. Check for Missing Library Parts and temporary missing objects in the Warnings panel
3. Compare the libraries loaded in the host file with those used in each hotlink source file
4. Ensure all libraries used by hotlink source files are also loaded in the host file
5. Align library types and versions across host and hotlink files (Global vs Monolith)
6. Review the Embedded Library, including the automatically created Hotlinks folder
7. Follow this process to resolve any missing libraries in the library manager.

Scenario A: Hotlinks use standard Archicad and custom office libraries not loaded in the host

This situation occurs when hotlink source files use a combination of standard Archicad libraries and custom office libraries (such as shared GDL object folders on a network drive), but those libraries are not loaded in the host file. Because placing a hotlink does not automatically import linked library parts, any library part not available in the host will appear as missing.

1. Open each hotlink source file and note all libraries listed under Libraries in Project in the Library Manager — including any custom office library folders
2. In the host file, follow this process to resolve any missing libraries and load each standard Archicad library and custom office library that is used by the hotlink source files.
3. Ensure that the file path to any shared office library folder is identical and accessible on all machines involved in the project.
4. If a custom office library is stored locally rather than on a shared drive, upload it to BIMcloud, so it is available to all project contributors
5. Update hotlink modules in the host via File > External Content > Hotlink Module Manager

Scenario B: Inconsistent use of global and monolith libraries across host and hotlink files

This situation occurs when the host file uses the Global Library while some hotlink source files still use legacy monolith libraries, or vice versa. Because Global and Monolith library parts are not compatible with each other, elements placed from one system will appear as missing when viewed from a file using the other system.

The recommended solution is to standardize all files to the Global Library. If full migration is not immediately possible, ensure each hotlink file contains only the libraries it actually uses, and that the host file includes all libraries used across all hotlinks.

1. Open each hotlink source file and check Library Manager to identify whether it uses Global Library packages (.libpack) or a Monolith library (Archicad Library XX.lcf)
2. Where possible, migrate hotlink source files to the Global Library:
   1. Open the hotlink source file in Archicad 28 or later
   2. In Library Manager, remove the Monolith library and add the relevant Global Library packages
   3. Replace placed objects that used Monolith library parts with their Global Library equivalents
   4. Save the file
3. If migrating a hotlink source file to the Global Library is not possible, ensure that hotlink contains only the libraries it actively uses — remove any unused or legacy library references
4. In the host file, follow this process to resolve any missing libraries in the library manager.
5. Reload the hotlink modules in the host file via File > External Content > Hotlink Module Manager and click Update

Scenario C: Host and hotlink files use different versions of monolith libraries

This situation occurs when the host file and hotlink source files reference different versions of the Monolith Library. For example, the host file may use Archicad Library 27 while a hotlink source file still uses Archicad Library 26. This version mismatch can cause missing library parts because elements from the older library may not be recognized by a file using the newer version.

To resolve this, migrate the host file and all hotlink source files to the same library version using the Monolith Migration Libraries:

1. Open the hotlink source file in the current version of Archicad
2. In Library Manager, click Migrate Libraries. This loads the Monolith Migration Library, automatically updates placed objects to their latest compatible versions, and removes outdated library references.
   • IMPORTANT: If using Archicad 29 or greater, see this guide for more details.
3. Click Reload & Apply, then save and close the hotlink source file
4. Repeat steps 1–3 for every hotlink source file used in the project
5. Open the host file and perform the library migration following the process described above.
6. Once all files use the same migrated library version, update hotlink modules in the host via File > External Content > Hotlink Module Manager and click Update
7. Follow this guide to resolve any missing libraries in the library manager.