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/p16022coll624/259/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-c87bae91-5761-42c0-9bf7-805f213eb683",
      "cw-799dbb74-f7ae-48ba-9ce7-335682dcf013"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-2c1c93b4-b83c-4ad7-9c94-b7bb1a275535",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll624/259/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-799dbb74-f7ae-48ba-9ce7-335682dcf013"
  }
}