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/p16022coll246/336/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-c3a9f21f-cc47-448f-b66e-e9a21db9073d",
      "cw-2b2a21a8-63cd-4479-b9bd-3749cb9e6963"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-98e96266-6542-44d0-8ff2-1223942de808",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/336/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-2b2a21a8-63cd-4479-b9bd-3749cb9e6963"
  }
}