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/p16022coll246/357/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-2f62d83c-6291-4539-ab7f-f194a01edf84",
      "cw-f3215a18-9665-4d9d-8bfe-8ea4663835ac"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-7dfc9eb8-0560-4af1-862e-8013a0ef699a",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/357/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-f3215a18-9665-4d9d-8bfe-8ea4663835ac"
  }
}