Recently on multiple projects (multiple apps in APS), we are seeing that on recently translated Inventor assemblies to SVF2 format that they are most of the time returning errors of “Invalid OTG header”, “Failed to parse OTG geometry”, and “Failed to parse geometry [some chinese text]”. I’ve tried the suggestion on Autodesk Forge Viewer – Invalid OGT header with SVF2 format but that did not resolve the issue.

I’ve upgraded the viewer reference from 7.82 to the latest 7.97. The error exists but with different information logged to the console…

OtgResourceCache.js:316 Error loading mesh. The service returned the following message: Unexpected zero length CDN resource received, path= undefined, allowedUrns= {“dXJuOmFkc2sub2JqZWN0czpvcy5vYmplY3Q6c3ZmMi1zdGFnaW5nLXBsNGx2aHpnb2xrOG4zamN3OGNkZWFjbGZpYWJ1enljLzU4MC0xNDI5LnppcA”:{“pharosId”:”_2REx1DTldSWOIB1bfF4pKTCmCQ”,”sharedRoot”:”dXJuOmFkc2sub2JqZWN0czpvcy5vYmplY3Q6c3ZmMi1zdGFnaW5nLXBsNGx2aHpnb2xrOG4zamN3OGNkZWFjbGZpYWJ1enljLzU4MC0xNDI5LnppcA/output/otg_files”,”version”:”0″},”dXJuOmFkc2sub2JqZWN0czpvcy5vYmplY3Q6c3ZmMi1wbDRsdmh6Z29sazhuM2pjdzhjZGVhY2xmaWFidXp5Yy8wNzItMDUwMC04OENfUG9zdC5pcHQ”:{“pharosId”:”JL2F1PeucfOyIfxuIKDGazA5nhE”,”sharedRoot”:”dXJuOmFkc2sub2JqZWN0czpvcy5vYmplY3Q6c3ZmMi1wbDRsdmh6Z29sazhuM2pjdzhjZGVhY2xmaWFidXp5Yy8wNzItMDUwMC04OENfUG9zdC5pcHQ/output/otg_files”,”version”:”0″}}
{hash: ‘꼹起봣䲙䛌㻔洺▛’, resourceType: ‘g’}

This problem started happening within the last two weeks on some Inventor files (2023) from multiple projects (different customer Inventor repositories).

What do we need to change in how we are loading the SVF2 geometries to keep this problem from occurring?