The component installer tells me to update my htaccess, what should I do?

Dropfiles has detected that your .htaccess is not up to date. It should result an impossibility to download other files than pdf.

The htaccess file in the latest Joomla version may differ from yours.
Why? Because during an update the .htaccess file is not always updated.

What should I do?
You can download a J3.9 new installation package and copy and paste the htaccess file.
You can also remove the line below from your htaccess file :
RewriteCond %{REQUEST_URI} /component/|(/[^.]*|\.(php|html?|feed|pdf|vcf|raw))$ [NC]