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/p16022coll246/409/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-0844e1b2-084e-4645-9481-0674e1e71d6f",
      "cw-5fe34693-f3fe-480a-a0c6-bbc792b3641d"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-21dd1bbc-c761-4825-bb89-9e50dfd0d479",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/409/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-5fe34693-f3fe-480a-a0c6-bbc792b3641d"
  }
}