Ractors

check this link

https://codex.www.ads-software.com/Changing_File_Permissions

i checked and your site working fine. Please update thread with your steps (how you resolved that) so other people will take benefit with that.

Don’t you need to change group of directory to www-data

what is your file permission for wp-content ?

That is due to file permission. change “upload” folder permission to 777.

check my post

https://www.ads-software.com/support/topic/visual-editor-disappeared-when-i-upgraded-to-39?replies=11#post-5476169

please try and let me know if problem fixed.

Don’t forget to take backup before doing anything.

at the time of update did you Deactivate plugins. ?

Its better always follow guide https://codex.www.ads-software.com/Updating_WordPress

OK now you need to use ftp and navigate to wp-content/. There you will see your plugins folder. Rename that folder to plugins.old. If you are able to login that means problem with your plugins.

Don’t forget to rename plugins.old back to plugins.

If that is plugin problem you need to deactivate all plugin. You can do that via ftp or phpmyadmin.

I prefer do that with FTP

Open wp-content/plugin folder and rename your plugin with .old. Like your plugins name is jetpack make that jetpack.old

Via style.css you can change value of h1 h2 etc

Open your admin panel > appearance > Editor

If you are using Default twentyfourteen Theme

then check line 148

h1 {
	font-size: 26px;
	line-height: 1.3846153846;
}

Change Font size to change H1 size

Update : Delete wp-includes\js folder and update new from wordpress 3.9 manually.

There is lots of unwanted files after upgrading to 3.9

Please report back if that work.

Ps : always make backup before doing anything.

Really this is strange. I have no problem on any of my site after updating worpdress to 3.9.

i am testing tinymsc advanced plugin on demo environment with latest 3.9

will update you result

Update : I am able to use editor without problem. Seems no problem with plugins. What theme are you using.

your site need deep investigation.

ask hostgator support they will fix that for you.

change folder permission to 777 and file permission to 666

3.9 have compatible issue with themes and plugins. Check with default theme.

1. disable all plugins and check
2. Switch to default theme and check

what version of wordpress are you running ?

on your home directory error_log