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/p16022coll246/326/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-0f16f660-53a0-4bbe-927c-fb7be58510ed",
      "cw-23c0b9b5-6555-4eb9-b721-07bd7e3e1dea"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-fdf98765-74f6-4bb8-a4fb-8f2b9b81ad03",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/326/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-23c0b9b5-6555-4eb9-b721-07bd7e3e1dea"
  }
}