Krishna

Can you switch to Twenty Thirteen theme and see if you still get that what/ . before your post title?

it is impossible to change theme and switch off the plugins I know nothing for wordpress.

If you can do that and check again using cloaking test tools that will help you know if the problem is caused by your theme.

Anyway, as your Google Webmaster Tools do not show any problems, I do not think your site is cloaked. If that is so, Google might be the first one to detect that.

Try this tool that shows that it’s not cloaking for Google:
http://www.seotools.com/seo-cloaking-checker/

Further, can you revert to Twenty Thirteen theme with all plugins off and check again using your favorite tool?

Then your only option is to reinstall Instant WordPress.

Try this: http://wordpress.org/plugins/paginate/

If it does not suit look for one from here:
http://wordpress.org/plugins/search.php?q=pagination

Download a fresh copy of Instant WordPress and try to install it. Possibly it may solve your problem if it just rewrites the missing files – not sure though. If that does not help, though possibly you may lose your MySQL database, just delete Instant WordPress and reinstall it from a fresh downloaded copy.

You may always keep copies of your database so that in such cases you can always restore your site if anything goes wrong.

1. When did you get the error – while trying to login to MySQL Admin?
2. Do you have a backup of your database?

This is the code you posted at your post:

<p>
<span style="color: #333333;">
<code> </code>
<a href="http://vimeo.com/79473933[/embed">http://vimeo.com/79473933</a>
</span>
<code>
<a>[/embed</a>
]
</code>
</p>
<p> </p>

Delete that and try posting as Jan suggested above:
[embed]http://vimeo.com/79473933[/embed]

If that does not work, try posting only this:
http://vimeo.com/79473933