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/p16022coll231/54/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-a47b4af9-8897-422e-ac0d-a5dad6c60257",
      "cw-c433a385-6cc9-43d5-bb49-e509f0846171"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-51cf802d-ef02-402c-b948-624fcc4f1a8c",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll231/54/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-c433a385-6cc9-43d5-bb49-e509f0846171"
  }
}