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/p16022coll246/378/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-0c00fd2c-4ce0-4af0-8e85-2ea67a7b103c",
      "cw-58b9c3c3-f0f3-47ed-a958-55f4a8cb8b32"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-98bf46c4-a514-402a-bbab-8c6cbead200b",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/378/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-58b9c3c3-f0f3-47ed-a958-55f4a8cb8b32"
  }
}