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/p16022coll246/331/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-4aa67ec3-0ebd-4eed-88b9-97b00fa23801",
      "cw-362d2abe-2133-434d-90bd-b18fc6c5910c"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-881c72b8-65ff-4f8f-8aac-203b302f81ef",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/331/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-362d2abe-2133-434d-90bd-b18fc6c5910c"
  }
}