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/p16022coll230/3531/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-7f73d9eb-3ff6-485b-a3fa-fa8b1369ba06",
      "cw-4d849fc3-19df-47e8-a87d-59dfdef733e1"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-b2f39d6a-00d0-447d-b908-d45a18807e50",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll230/3531/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-4d849fc3-19df-47e8-a87d-59dfdef733e1"
  }
}