CRDOWNLOAD is a temporary file extension used by the Chrome web browser. Files with this extension are called Chrome Partial Download Files, so seeing one means that the file isn't completely downloaded.

Partial downloads are due to the fact that either the file is still being downloaded by Chrome or that the download process was interrupted, so it's only a partial, incomplete file.

If the CRDOWNLOAD file extension is being used because Chrome is actively downloading something, it will usually automatically remove the ".crdownload" portion once the download finishes