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/p16022coll246/154/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-0df1dd8a-3ceb-49dc-a631-8e302cabc2b1",
      "cw-aa46965a-a10b-4e6d-a22c-4503d7caf12b"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-85db4722-9aa5-4ec6-8c4d-c9556d063bcc",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/154/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-aa46965a-a10b-4e6d-a22c-4503d7caf12b"
  }
}