When I add a new site (ftp), it doesn't put the files when I do ctrl+s. In my other sites it is working. I have this problem for some time now. Every time I add a new site and add an ftp server It doesn't put the file after hitting ctrl+s. What can be pthe problem?
Depends on your preferred workflow, your skillset and your confidence level.
Most people comfortable with web tools and HTML/CSS are probably OK with auto upload on save because they know what they are doing and can fix any typos or mistakes which they make.
Beginners are better off not using it because they can easily break a website by inadvertently moving or deleting crucial markup (unbalanced div tags are common) and then spend hours fixing it because they don't know what they're looking for or what their tools are telling them; they often hit the forums in panic and desperation in the process.
The trial and error approach mixed with panic often makes things worse and they may not have a good copy of the page to fall back on because they've overwritten it with their bad copy.
I prefer not using auto upload on save. I always do my editing then manually upload.