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/mgs/945/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-6df3dc81-4b3d-4853-943a-7529e80e53e9",
      "cw-bd2ad3ba-3d9a-4574-a0bd-54b5143ee428"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-3bba1565-102e-4c24-8131-57a62967e0ef",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/mgs/945/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-bd2ad3ba-3d9a-4574-a0bd-54b5143ee428"
  }
}