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/p16022coll624/283/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-52ee61a7-eb34-4709-ab9c-e1fffa144c0f",
      "cw-5baacf21-f1fb-4415-836d-0fa405c09702"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-66375eb5-2b2f-4935-89a5-441edeed462c",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll624/283/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-5baacf21-f1fb-4415-836d-0fa405c09702"
  }
}