dianping/cat · error · Error

You can't provide both 'acceptedFiles' and…

Error message

You can't provide both 'acceptedFiles' and 'acceptedMimeTypes'. 'acceptedMimeTypes' is deprecated.

What it means

Dropzone supports two ways to restrict accepted files: the older acceptedMimeTypes (deprecated) and the newer acceptedFiles (comma-separated extensions/mime globs). Supplying both at once is ambiguous, so the constructor rejects the combination with an explicit deprecation message.

Solutions

1. Delete acceptedMimeTypes and keep only acceptedFiles: { acceptedFiles: 'image/*,.png,.jpg' }.
2. Search config files/data attributes for acceptedMimeTypes and remove all occurrences.
3. Migrate mime strings: acceptedMimeTypes:'image/jpeg' becomes acceptedFiles:'image/jpeg' (same syntax is accepted).

Example fix

// before
new Dropzone(el, {
  url: '/upload',
  acceptedMimeTypes: 'image/*',   // deprecated
  acceptedFiles: '.jpg,.png'
});

// after
new Dropzone(el, {
  url: '/upload',
  acceptedFiles: 'image/*,.jpg,.png'
});

if (opts.acceptedMimeTypes) {
  opts.acceptedFiles = opts.acceptedFiles || opts.acceptedMimeTypes;
  delete opts.acceptedMimeTypes;
}
new Dropzone(el, opts);

When it happens

Trigger: new Dropzone(el, { acceptedFiles: '.png,.jpg', acceptedMimeTypes: 'image/*' }); configuration carried over from an old Dropzone 3.x setup where new options were added without removing the deprecated key; data attributes or JSON config that contains both keys.

Common situations: Upgrading dropzone versions and layering the new acceptedFiles on top of legacy acceptedMimeTypes; shared config objects merged from defaults (old) and overrides (new).

Related errors

• No URL provided.
• Dropzone already attached.
• failed to require
• Invalid date format.
• Invalid dropzone element.

AI-assisted analysis of dianping/cat@e815e74d4c (2026-08-14). Data as JSON: /api/errors/5692d4d1ab7fb542. Report an issue: GitHub.

Appendix: source

Thrown at cat-home/src/main/webapp/assets/js/uncompressed/dropzone.js:598

      }
      if (this.element.dropzone) {
        throw new Error("Dropzone already attached.");
      }
      Dropzone.instances.push(this);
      this.element.dropzone = this;
      elementOptions = (_ref = Dropzone.optionsForElement(this.element)) != null ? _ref : {};
      this.options = extend({}, this.defaultOptions, elementOptions, options != null ? options : {});
      if (this.options.forceFallback || !Dropzone.isBrowserSupported()) {
        return this.options.fallback.call(this);
      }
      if (this.options.url == null) {
        this.options.url = this.element.getAttribute("action");
      }
      if (!this.options.url) {
        throw new Error("No URL provided.");
      }
      if (this.options.acceptedFiles && this.options.acceptedMimeTypes) {
        throw new Error("You can't provide both 'acceptedFiles' and 'acceptedMimeTypes'. 'acceptedMimeTypes' is deprecated.");
      }
      if (this.options.acceptedMimeTypes) {
        this.options.acceptedFiles = this.options.acceptedMimeTypes;
        delete this.options.acceptedMimeTypes;
      }
      this.options.method = this.options.method.toUpperCase();
      if ((fallback = this.getExistingFallback()) && fallback.parentNode) {
        fallback.parentNode.removeChild(fallback);
      }
      if (this.options.previewsContainer !== false) {
        if (this.options.previewsContainer) {
          this.previewsContainer = Dropzone.getElement(this.options.previewsContainer, "previewsContainer");
        } else {
          this.previewsContainer = this.element;
        }
      }
      if (this.options.clickable) {
        if (this.options.clickable === true) {

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