Try to save the file as a text file if Firefox shows the page source in a tab.

Current Firefox version open the page source in a Tab (view_source.tab) and saving this page works differently. You get html code as you see it with context highlighting code as you will notice if you check the file in a text editor.

cor-el said

Try to save the file as a text file if Firefox shows the page source in a tab. Current Firefox version open the page source in a Tab (view_source.tab) and saving this page works differently. You get html code as you see it with context highlighting code as you will notice if you check the file in a text editor.

This helped but not by saving as a txt file. That just gives me html code in a txt file instead of an htm file. What helped was setting the view_source.tab option to false. Now the page source opens in a new window, and when I save it, when I open the saved file in the browser, it appears as a web page (as before). I would not have thought that there would be a difference in the htm files saved via tab or window, (and it seems strange), but anyway, problem solved, thanks.

Why do you save by opening and then save the page source?

I just save any web page by file -> save page as -> web page html only or -> web page complete (Sorry, I run german FF, so I am not sure about correct english menu...)

so it is always saved as .htm/.html file.

I set my FF-config "view_source.editor.path" to notepad++, which I use to retrieve information from the webpage.