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/p16022coll246/409/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-e619ef02-16db-42ab-88bd-65351169b93f",
      "cw-162bc34c-5c00-4c43-a0d8-d0c85c9b0e24"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-fbedada6-199b-4258-82df-04c5cf021a97",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/409/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-162bc34c-5c00-4c43-a0d8-d0c85c9b0e24"
  }
}