Summary
Here is an example of what I just traced through for installing meshpack plugin in my unreal engine…
DNS and TCP/443 are healthy for www.fab.com, api.epicgames.dev, cdn.quixel.com, Akamai, CloudFront, and Fastly. The
CDN download works: cdn.quixel.com/...FabLauncher_ue5.7...zip returns 200 OK.
The failing endpoint is still:
https://www.fab.com/e/artifacts/MeshPack8fbfed5e86b8V7/manifest
It returns 403 Forbidden from Cloudflare, and the Launcher logs show the same Cloudflare “security check” HTML page
being returned where Fab expects manifest data. That causes MD-0011-0 / IS-EO-Lnc-BldInfo:Http-403 and empty Fab
download fields.
When you’re using non interactive endpoints you cannot use an interactive mitigation process like what cloudflare injects or the service will just not work. This completely breaks the ability to use your applications.
What type of bug are you experiencing?
Plugins
URL where the bug was encountered
https://www.fab.com/e/artifacts/MeshPack8fbfed5e86b8V7/manifest
Steps to Reproduce
Fresh install of apps or plugins may trigger cloud flare to show human validation in which case it fails due to the fact that there is no human in the loop…
Expected Result
Retrieve manifests directly from a non interactive location so fab can install them. Ideally set a session to the current authenticated fab client which bypasses cloudflare.
Observed Result
Breaking change… cannot install required plugins.
Platform
Fab install to engine && Epic games → Library → Install to engine… both fail.
Operating System
Windows 11 Pro
