Strange model surface behaviour after extrude

ich just started with blender after watching some videos of blender guru.
I followed the latest beginner tutorial and tried to build a mug.

While he was talking about something
I fiddle a little around and started to extrude and made something wrong.
so i deleted my extrud and pressed here and there.

And then i realized that something is wrong with one face.

You can see the strange face with the subdivision surface modifier.

without the subdivision surface modifier you cant see this but it is still there

And if i connect the handle with the mug, the new faces will look strange as well

does anybody know, what is going on here and how i can fix this?


No one knows for sure because you didn’t include an example .blend of the problem, and the screenshots are scaled so the feedback from the interface is also lost

Darker faces like that usually mean the face directions (normals) are pointing inside, flipped compared to the faces nearby. Select all, ctrl+N to make normals consistent and pointing out. Might not work if there are mesh errors.

Looks like you’ve got a duplicate face(extruded to zero distance) Do W->R to remove doubles.

thanks for the help.

i tried to make the normals consistent but it didnt helped.
But thx for the shortcut.
i will try to remeber this for further modeling problems that may occur

The doubles removing does the trick.
now its all good again.

thx alot for this fast help.