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/p16022coll230/1521/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-97bc6cf3-f898-4c3a-9f42-0484033624c0",
      "cw-f5d4e1ef-2547-4af5-9fbb-ee3bbd936d27"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-978fbe99-f9e0-42ae-a78e-3ed802c3e65a",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll230/1521/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-f5d4e1ef-2547-4af5-9fbb-ee3bbd936d27"
  }
}