Mirador viewer

SyntaxError: Unexpected token '<', "<!DOCTYPE "... is not valid JSON

{
  "manifest": {
    "error": "SyntaxError: Unexpected token '<', \"<!DOCTYPE \"... is not valid JSON",
    "id": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll231/31/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-eb8e2dd8-8cad-476c-9d38-394ad3a03d1c",
      "cw-0976d088-241a-4a27-9ced-b45460ede1a4"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-af2e8bd8-e06f-42de-9884-e540eda81ab3",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll231/31/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-0976d088-241a-4a27-9ced-b45460ede1a4"
  }
}