Opening a UE5.8 project and seeing "DatasmithGLTFImporter plugin could not be found" isn't a corrupted install — Epic pulled the legacy glTF and Datasmith glTF importers out of 5.8, the last planned major UE5 release before UE6, and routed everything through the Interchange Framework instead. Click "Disable missing plugins and continue" when that dialog appears; your project opens fine, but every glTF/GLB you import from here on uses a different dialog with different defaults, and two of those defaults will bite skinned characters and off-center props specifically.
What Interchange changed about glTF import in UE5.8
Interchange isn't new — it's been the default FBX path since 5.0 — but glTF only moved onto it as the legacy importer got deprecated. Drag a GLB into the Content Browser now and you get the Interchange Pipeline Configuration dialog instead of the old glTF import options window. Two changes matter immediately: material creation vs. reuse is now a labeled setting instead of an implicit checkbox, and pivot/offset handling — which the legacy FBX-style importer exposed directly — isn't surfaced in the glTF pipeline at all. A model authored off-origin in Blender or exported from BitSoul's 3D Studio at (0,0,0) imports fine; one with its origin dragged away from world zero lands off-pivot with no in-dialog fix.
The glTF spec itself caps a single joints/weights accessor pair at 4 bone influences per vertex — JOINTS_0/WEIGHTS_0. Files with more complex rigs carry a second pair, JOINTS_1/WEIGHTS_1, for 8 influences total. That's not an Interchange bug on its own, but Epic's own bug tracker has an open report of the Interchange glTF path dropping straight to 4 even when a file ships both sets — worth ruling out before you assume your rig is broken. Confirm what your source file actually has before you start debugging the importer:
gltf-transform inspect character.glb | grep -i -E "joints|weights"If that shows both JOINTS_0 and JOINTS_1, the file is fine and you're hitting the truncation bug, not a rig problem — see our glTF 4-bone weight limit fix for the workaround.
Set up the Interchange Pipeline Configuration correctly
For a game-ready GLB — a character, a weapon, a prop — the dialog needs four decisions, not the defaults:
- Choose Pipeline Stack (top-left dropdown): pick Assets, not Scenes. Scenes is built for Datasmith-style full-level composition and will try to spawn actors and a level hierarchy for what should be a single static or skeletal mesh.
- Common Meshes → Convert Static Meshes to Skeletal Meshes: leave off unless you're importing a rig — it's on by default in some 5.8 preview configs and silently skeletalizes static props.
- Materials → Material Import: UE5.8 regrouped this into an explicit "Create new materials" vs. "use existing materials by name" choice. Set it explicitly on first import — the default silently creates a fresh material instance on every reimport instead of overwriting, and you end up with
M_Character_01,M_Character_02,M_Character_03piling up in the same folder. - Click Import, not Import All if you're bringing in a batch with mixed static/skeletal content — Import All applies one pipeline stack to everything in the batch.
Test this against a rigged asset before you commit to the workflow on a full batch — something like the Heavy Assault Trooper has a normal single-set skeleton, so it's a clean way to confirm your pipeline stack settings before you run them against 40 production files.
Legacy importer vs. Interchange: what actually changed
| Behavior | Legacy glTF / Datasmith Importer | Interchange (UE5.8) |
|---|---|---|
| Pivot/offset control | Exposed in-dialog | Not exposed — fix at export |
| Material create vs. reuse | Implicit checkbox | Explicit labeled setting |
| Reimport behavior | Overwrites by default | Can duplicate materials if reuse isn't set |
| Bone influences per vertex | Reads both joint sets (8 max) | Known bug truncates to 4 on some files |
| Import Into Level support | Full scene formats | Currently only glTF and MaterialX |
| Plugin status in 5.8 | Removed, disable-and-continue prompt | Default path |
Gotchas that show up after the migration
Reimporting an existing asset over itself behaves differently than it did on the legacy path — without the material setting from step 3 above, each reimport can leave the old material instance orphaned in the folder rather than updating in place, so check your Content Browser after a batch reimport rather than assuming it's clean.
Collision is a separate problem from the importer swap and predates it: plain GLB imports in UE5, Unity, and Godot alike don't carry collision data unless the source file defines it, Interchange or not. If your imported mesh falls through the floor, that's not migration-related — see why GLB imports have no collision across engines for the fix.
If you're reimporting assets that already broke under 5.7's Substrate default, fix that first — Interchange won't resolve a Substrate material conversion issue, it just changes how the file gets in the door. Our UE5.7 Substrate glTF metal fix covers that separately, and our glTF reimport breaking scenes post covers reimport-specific scene corruption that's unrelated to the plugin swap.
Batch-importing a folder of GLBs through Interchange applies whatever pipeline stack you last configured to every file, silently — there's no per-file override in a batch run the way there was with the old importer's per-asset dialog. Run one test file through manually, confirm the four settings above, then batch the rest. Projects with a mix of static props and rigged characters in one folder should split into two batches by type rather than relying on Interchange to detect which is which — the auto-detection is what causes the unwanted static-to-skeletal conversion from step 2.
A free BitSoul account's two monthly downloads cover testing a pipeline stack like this against a real GLB before committing; commercial use is included with paid memberships — see pricing for tiers.
This post is part of the Ultimate Guide to Free 3D Game Assets — BitSoul's complete reference for formats, texturing, rigging, optimization, and engine integration.