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/p16022coll246/257/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-d97706a4-c351-40f1-981b-e35467b83800",
      "cw-eaac5cb6-5328-411d-b129-f66578ecc134"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-83613b7b-617d-44a4-86a4-1f05f2c4d63c",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/257/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-eaac5cb6-5328-411d-b129-f66578ecc134"
  }
}