Elementor attempts to read the uploaded archive with PHP’s ZipArchive class. If the class cannot open the file, Elementor reports the archive as empty. The error appears when the file that reaches the importer contains no data or cannot be interpreted as a ZIP.
Typical triggers include a corrupted download, server limits that truncate the upload, missing PHP zip extension, or file‑system permissions that prevent the temporary file from being written. Security modules may also strip the payload, leaving a zero‑byte placeholder.
When the importer receives an empty stream, it stops immediately and displays the message. No progress bar appears and the kit never registers in the Installed Kits list.