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/p16022coll246/320/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-b7cb4426-eb24-42f6-b3cd-6b253cd436db",
      "cw-14b7085b-3e69-4042-a790-c4e6637172db"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-445351d4-399d-4189-9d29-32567f73a599",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/320/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-14b7085b-3e69-4042-a790-c4e6637172db"
  }
}