Recent changes to the Google Chrome browser is causing an issue with saving files in BC Calc® software Offline mode. The action works like a download and the browser sees the file as potentially harmful.
You can click "Keep" and continue with the download, or click the Downloads folder and choose Keep.
By making a change to the security settings for the BC Calc Offline web site you will be able to download files without the error.
Copy this URL and paste into a Google Chrome browser:
Then scroll down to ‘Insecure content’. Change this from 'Block' to 'Allow.'
You may need to close and restart the browser but this should allow saving BC Calc offline files without error.