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/p16022coll231/29/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-c8cb1e42-28f5-46d0-a199-8caea8fe5be8",
      "cw-95192ed7-f822-4c35-a1b7-8e9a8ce43ad9"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-b2f12633-8bb6-498d-a778-3aef83ba9aaf",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll231/29/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-95192ed7-f822-4c35-a1b7-8e9a8ce43ad9"
  }
}