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-246ba4ed-2451-43b7-92ec-e2e8cc0106ef",
      "cw-3a683225-db59-4d41-b8e4-c99632a853d4"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-7fcbabd7-31f2-43ab-a70e-d9e1a9d5302c",
    "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-3a683225-db59-4d41-b8e4-c99632a853d4"
  }
}