Hello, this is a very simple thing to change.

Click here for the steps --> https://support.mozilla.org/en-US/kb/change-firefox-behavior-when-open-file#w_changing-download-actions

Hi simonc8, if the first reply doesn't resolve the issue, the problem could be how the bank site describes the file in the Content-Type header. If it doesn't specifically indicate that it is a CSV file, but instead says it is a generic downloadable file, then Firefox won't match up the download with the instructions for CSV files.

But unless your bank coincidentally changed how it identifies downloads at the exact moment you did your Windows update, that might not be the issue...

If you want to investigate that further:

I created an add-on to view the Content-Type header sent with each download, and create overrides for certain file extensions. So if a site consistently sends the wrong type for .csv files, you could create an override for that.

https://addons.mozilla.org/firefox/addon/content-type-fixer/

Thanks for the answer vpabloluis16. The strange thing is there were four entries for different types of .csv files, and three of them had been switched to Excel, and the fourth - called CSV (text/file) - was set to Save file. Obviously the downloads from the bank were identified as the fourth sort.

I have now made the change and checked that it works.

Brilliant. Thanks. Another satistifed customer!

Good to know, glad you got it working simonc8.