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-07d6a8d4-4df4-4094-950f-d4bc5dcbaaff",
      "cw-ceddb5c0-9825-4379-9e45-2ff7f55ed566"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-004bcaab-a0f2-403e-825b-e003d76a6d24",
    "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-ceddb5c0-9825-4379-9e45-2ff7f55ed566"
  }
}