Closing an open contour - Tried some tips from the forum

[rickonvb]

Hello everyone!

I followed some of the tips that were found here... but I still cannot extrude this object.
This object was made from a company logo using splines.

Can anyone help me out on this one?
I have checked for short line outide the surface, the "sketch tool check" says it is ok for the extrude or cut, regular or thin...

View attachment logo.zip

Thanks!