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/p16022coll624/318/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-60ec73c5-c61d-498b-9e57-36bb89bce0c8",
      "cw-a8da63c2-3e0c-4472-9d85-6ef8a4be67bd"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-64356167-ac54-4966-82ae-8e7461d22ac1",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll624/318/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-a8da63c2-3e0c-4472-9d85-6ef8a4be67bd"
  }
}