Why does CATIA stop me being able to sketch?

I can make my first couple sketches fine but after a while it stops working, no error message or anything I just cant create a new sketch.
Probably a beginner error so dont feel like you're patronising me haha.

Sorry if this isn't the place for beginner questions but it seems like nowhere is.

1 Answer

Looks like you're in "sketch mode" trying to draw a circle in Sketch.8. The prompt in the lower-left corner says "pick a center point". I'm guessing you can't?

But it also looks like the screen is dimmed (grayish), which probably means you have the tree active. Click on the axis system in the lower-right, and see if that helps by re-activating the geometric screen and lets you work on the sketch again.