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/p16022coll624/311/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-2bce66ed-e97a-443a-9b0f-347a1923eb07",
      "cw-fd682952-b45c-4309-aaf3-7b7f827d7183"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-44d2c676-62a1-46cc-a695-31c3afb34d75",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll624/311/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-fd682952-b45c-4309-aaf3-7b7f827d7183"
  }
}