TypeError: Failed to fetch

{
  "manifest": {
    "error": "TypeError: Failed to fetch",
    "id": "http://jaegerstaetter-test.literaturtirol.at/omekas/iiif/2/1059/manifest",
    "isFetching": false
  },
  "window": {
    "autoScrollAnnotationList": true,
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-8ed591d0-4007-40c0-bd20-506a641058c4",
      "cw-ea22f188-6454-4848-8fcf-eb43cef36d94"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-e7b02f24-ab01-4ac9-8b85-8740ea490294",
    "manifestId": "http://jaegerstaetter-test.literaturtirol.at/omekas/iiif/2/1059/manifest",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-ea22f188-6454-4848-8fcf-eb43cef36d94",
    "loadedManifest": "http://jaegerstaetter-test.literaturtirol.at/omekas/iiif/2/1059/manifest"
  }
}