Error Message calling for geometric data

[torme]

From Beginner Tom using Academic version.

When I go from Sketch to Extrude I often get this error message when I hit the OK green check.

"Incomplete Section" - reason - "Section must contain geometric entities for this feature"

Where did all the entities go?  Figure is blue.  What does blue color means?

[sm]

‌Tom, your sketch does not for a single closed area and that is why Creo will not accept it for an extrude feature. While working on you're sketch, it should shade the interior of the closed area in yellow. If it does not, you will not be able to extrude with it. In your example, you have two small horizontal lines outside your oval. If you remove them you should be okay.

There is is a set feature validation tools near the end of the Sketcher toolbar to check for closed area, overlapping entities and others. Use them to make sure you're sketch is what you expect it to be.

[torme]

Thanks for the advice.  I found some validation tools under "inspect"

Some weird results with unclosed sketches.

After hitting Sketch OK

Extrude

After hitting Extrude OK

No gray solid, of course.  But interesting new colors. 

[torme]

Here we go again.  How do I recover geometric entities when I get this blue color?  Have I lost forever the data?  This is after I hit the OK button on Sketch, tried Extrude and got a 2D sketch, then went back to Sketch and got this error message.

[Kevin · Accepted solution]

Although the sketch is extruded it is a surface. The only way to extrude an open sketch as a solid is to select the thicken icon in the extrude dashboard. The orange color is a preview of what the geometry will look like and the dark blue identifies the geometry as surface geometry. As far as the error message are you creating the geometry as cunstruction geometry? There is an icon that can be selected that toggles whether the entities created are construction geometry (phantom lines) or sketch geometry (solid lines) which I don't see in your image. If you exit a sketch that just has construction geometry I don't believe you can get that geometry back. I'll try to upload some images if you don't find the options.

[torme]

Many thanks.  The color code is gradually sinking in. Reddish orange is good.