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/p16022coll230/689/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-9c35ed69-dfe3-4573-bfda-a1799e996541",
      "cw-84d0afc5-9ca8-44f9-a8c6-833dddfded1f"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-6f21f068-c99a-4cd4-9d21-6142d7634eda",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll230/689/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-84d0afc5-9ca8-44f9-a8c6-833dddfded1f"
  }
}