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/p16022coll246/434/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-c46ef6f5-6234-4773-9ece-db313966af1d",
      "cw-5d1c2dba-98a3-4bfa-9aa6-983c5c27b11a"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-ff3bd048-11b7-4806-a188-0a3dac7dddc5",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/434/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-5d1c2dba-98a3-4bfa-9aa6-983c5c27b11a"
  }
}