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/p16022coll229/598/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-08af4727-1bfc-4bcc-8d26-fd674856513d",
      "cw-fb018242-34ff-448b-bcae-9ec41074f4f2"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-34551efb-a7e9-48de-adcf-b93e824c3f9e",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll229/598/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-fb018242-34ff-448b-bcae-9ec41074f4f2"
  }
}