winrar-x64-521b2.exe refers to the installer for WinRAR version 5.21 Beta 2 (64-bit) , which was released by RARLAB in early 2015.
Better Path Handling: It resolved a bug where paths could be truncated when extracting selected files from multiple folders using "Flat folders view" . winrarx64521b2exe+better
Speed: WinRAR is traditionally faster at compression than 7-Zip at default settings but often results in slightly larger file sizes. winrar-x64-521b2
-> Properties -> Digital Signatures. Ensure it says "win.rar GmbH". Run a Virus Scan : Always upload the file to VirusTotal before running it. Consider the Latest Version : Unless you have a specific need for 5.21, the latest version of WinRAR “Corrupt archive” errors: try Repair in WinRAR (Tools