Picture shows no preview or „Speichern“ does nothing

Area: Account and access · Updated: 3 Nov 2026 · Auf Deutsch · All articles

Symptoms

  • A normal PNG or JPEG shows „Vorschau in diesem Browser nicht möglich, das Bild wird mittig zugeschnitten.“ instead of a preview (before 3 Nov 2026).
  • „Speichern“ shows no spinner, no success and the old picture stays.
  • „Die Datei lässt sich nicht lesen. Liegt sie in einem Cloud-Ordner …?“
  • „Dieser Browser kann HEIC nicht anzeigen …“ or „Das Bild lässt sich nicht öffnen …“

Cause

  • Until 3 Nov 2026 the editor asked the browser only once whether it could decode the picture (HTMLImageElement.decode()). Chrome can reject that call for reasons that have nothing to do with the format, and every rejection was treated as „this browser cannot show the format“: no preview, a centre crop, and on „Speichern“ the whole file was read and uploaded in parts with only a small grey line as feedback, so nothing visible happened.
  • Since then the picture is read once and decoded in two independent ways (createImageBitmap with the EXIF orientation, then a normal image load). Only when both fail is the format really not shown; a HEIC is then converted on the server and opens the cropper too.
  • „Die Datei lässt sich nicht lesen“: the browser could not read the file within 20 seconds, typically an online-only file of Dropbox, iCloud Drive or OneDrive that is not on the computer yet.
  • „Das Bild lässt sich nicht öffnen“: the file is damaged or is not the picture its name says.
  • „… nicht klein genug speichern“: even the smallest size of the crop is above the limit (favicon 128 KB, logos 256 KB), e.g. a very noisy photo as favicon.

How to fix it

1. Choose the picture again

  • In the dashboard: X3 Konto › Profil › Profilbild › Anderes Bild wählen
  • With Claude (MCP): profile_avatar_set {"url":"https://example.com/portrait.jpg"}

The cropper opens with a round mask and the preview in 64 and 32 px; drag, zoom with the wheel, two fingers or + and -, then „Speichern“ (spinner, then „Profilbild gespeichert.“). Through Claude the centre of the picture is used, or the given crop.

2. Make a cloud file available offline

  • In the dashboard: Finder › right-click the file › Make available offline
  • With Claude (MCP): No MCP tool (the file lives on the person's computer; X3 only sees what the browser can read)

Or copy the picture to the desktop first and choose it from there.

3. Logo of an organization or project

  • In the dashboard: X3 Konto › Organisationen › Logo
  • With Claude (MCP): org_logo_set {"org":"nordlicht-studio","contentType":"image/png","data":"iVBORw0KGgo="}

Square mask, zoom out until the whole logo fits; transparency is kept. Project logos: Einstellungen › Projekt › Logo (project_logo_set).

How to tell it worked

  • After choosing a picture the cropper with preview appears; after „Speichern“ the success message and the new picture in the header.