Use Blender to create geometry, Sollumz to prepare GTA asset structures, and CodeWalker to inspect and place the results. Your first pipeline test should be an original, uncomplicated prop. A complete interior introduces too many variables before you know that export works.
Record the toolchain
Create a short toolchain.txt beside the project. Record the Blender version, Sollumz version, CodeWalker build, GTA edition, game build and intended FiveM target. These are facts about your project, not values to copy from a stranger’s configuration.
Freeze those choices for the first working export. A newer tool can be useful, but upgrading all three applications in the middle of a failure makes the failure harder to isolate.
Install Sollumz through its documented route
The Sollumz installation documentation describes its extension repository for Blender 4.2 and later. In Blender’s extension repository settings, add the repository supplied by Sollumz, then install the regular release. A separate development option is available; choose it intentionally rather than because its name sounds newer.
Older Blender versions use a different add-on installation route. Confirm compatibility in the release notes instead of assuming that an arbitrary Blender ZIP and an arbitrary Sollumz ZIP will work together.
After installation, open a new Blender file and locate the Sollumz tools. Save a small test project immediately. This establishes that the extension is available before you start troubleshooting your model.
Build an original test object
Use a simple block or bench that you created yourself. Keep the shape modest and use a distinctive project prefix, such as cw_. The point is to recognize this exact asset in CodeWalker and in your test server.
Check the object’s dimensions, transforms, normals and material assignment. Do not use an imported commercial MLO as your setup test; permissions, dependencies and unusual asset structures would complicate an otherwise simple exercise.
Prepare the object as a GTA drawable using the version-matched Sollumz documentation. An ordinary Blender material is not automatically an exported GTA shader setup. Keep rendering settings and export settings separate in your notes.
Prove the round trip
Choose one documented interchange path and follow it consistently. The Sollumz interior export guide describes exporting XML and importing that output through CodeWalker’s RPF Explorer to create game-format files. Some tool combinations expose other routes; do not silently combine them.
Open the resulting asset in CodeWalker. Confirm that its shape, scale and appearance are recognizably the test object. Save a screenshot alongside the version notes. A successful Blender render does not prove that the game-format export succeeded.
Do not attempt to export every object in a cluttered scene. Keep source collections and export selections explicit, and check that required objects are visible when using a workflow whose exporter depends on visibility.
Add the definition and placement
An exported model is not yet a map. Create or inspect its archetype, then place an entity referring to that archetype in a small YMAP. Keep names consistent across the asset, definition and placement.
Use the file-format guide when the distinction is unclear. The FiveM resource tutorial covers delivery of a custom YTYP rather than just vanilla prop placements.
Set a clear pass condition
Before modeling an interior, require the prop to pass four checks: it opens in CodeWalker, appears at the intended coordinates on your development server, remains present after reconnecting, and can be reproduced from the saved source project.
Keep a copy of that working state. Your next export should change one thing: perhaps a material or an extra piece of geometry. If it fails, the difference between the two exports is small enough to inspect.
Once the round trip is repeatable, continue with creating a FiveM MLO. Keep the first room as simple as the first prop.