My WordPress blog had an odd problem, all on the blog, worked just fine except the Widgets add new widget drag and drop functionality.
As there was new version of wordpress available I tried updating but this fixed the missing drag and drop widget functionality neither, so finally after a bit of googling and experimentation to follow suggested fixes like using the enable Accessiblity Mode button on top Widgets.Thus the common suggested fix that worked for most of the people who stumbled upon this annoying wordpress bug was to simply nagivate to:
Appearance -> Widgets -> Screen Options -> Enable Accessibility ModeAs for me pressing over the Screen Options was impossible (nothing happened when I pressed over it), finally I've found a hack
The hack is quite simple, all I had to do is just pass a variable ?widgets-access=on to the widget.php php script
Therefore the fix to the problem was as follows http://blog.mysite.com/wp-admin/widgets.php?widgets-access=on
And done, FIXED!