Visual editor not working in 3.5.1

Hi,

After two years not logging in, I went in yesterday and noticed that it has automatically been updated to 3.5.1, and I was using a WooThemes theme, which it stated was also up to date with WP current version.

I started to delete the themes that I’ve installed long ago..and accidentaly deleted the twenty twelve without realising.

Then I start to make changes (still on woothemes) by uploading an image for background, but after selecting from my pc, it didn’t upload and was just blank screen in the image window.
I checked on a past post, and found that the visual tab has no editing buttons and it was all blank, but when I go to the website, the post is still there so I click on “text” and back to visual but it was stucked in text. Then I tried new post, still stucked on text editor.

I search around and found several suggestions, I deactivate all (only have one) plugins, realised I deleted twenty twelve so revert to twenty eleven, but still not solved. Also tried check and uncheck the “Disable the visual editor when writing”. I then found article Using Your Browser to Diagnose JavaScript Errors, turned on script debugging “define(‘SCRIPT_DEBUG’, true);”
and voila..the problem solved. But article said to turn back off and tell the volunteers.

So I turned it off and problem came back, however I can now upload image to library but unable to click on it and use. THere was no error in the console while at this page. For new post, i can change back to visual tab, but there was still no editing buttons on the visual editor, when I type, cursor was moving but it was blank. Basically, I still can’t post.

Before posting to forum I decided to read further and check on the error and this is what I got on IE..

For Add new post
SCRIPT5007: Unable to get value of the property ‘split’: object is null or undefined
wp-tinymce.php?c=1&ver=358-23224, line 32 character 365

SCRIPT5007: Unable to get value of the property ‘add’: object is null or undefined
post-new.php, line 1124 character 5

I am a totally non-tech, took me an hour to find where wp-config file is. I have no idea at all what the above script means and would really appreciate any help from the volunteers here.