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/p16022coll246/298/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-3fe516c1-0315-4fba-b692-e00bb6b5f9e4",
      "cw-a231b86f-7294-4cee-9af5-b8832e4d1b2c"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-02dc9de2-7d9c-4cb9-812f-7995e09ae65c",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/298/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-a231b86f-7294-4cee-9af5-b8832e4d1b2c"
  }
}