Can someone help me understand why my mod wont post?

BACKEND (E): [RestApi] ID:[24] TYPE:[EBREQ_WORKSHOP_UploadAssetFile] Error Code:524 - Unimplemented 5xx, apiCode="", uid="", message=""
DEFAULT (E): Uploading failed! Reason: ""

It freezes here on the last stage that says "Publishing Project. Please Wait..." then just skips to fail giving this code in the log console.