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/p16022coll624/308/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-347bf3f9-cd87-471b-9899-e168976dacfd",
      "cw-713dc22e-34fb-4a7b-a495-de1d97afe3b7"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-b943141a-d308-4cd8-9d6f-a95d41621bf8",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll624/308/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-713dc22e-34fb-4a7b-a495-de1d97afe3b7"
  }
}