I am prompted "Open with" or "This is not an encrypted file" when I open an encrypted file and folder?

"Open with" prompted: You don't install a proper program or encryption software. Because "Open with" appears only the system cannot find the associated program to open the file.

"This is not an encrypted file" prompted: The file or folder is not encrypted by Best Folder Encryptor, or it is not an encrypted file.

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