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/p16022coll230/921/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-41d73fb6-77e1-4d9c-a709-d125244d7296",
      "cw-798deb59-d3e7-4cad-a2a9-65699eaaa7ef"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-3074dbaf-ca06-40c2-b8a0-281d08afc19f",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll230/921/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-798deb59-d3e7-4cad-a2a9-65699eaaa7ef"
  }
}