It's strange that any face edge or point can't be selected in assembly sometimes,and sometime the mouse arrow become as the following picture show,is anyway to solve it?
That's interesting. I haven't seen the stamp-out cursor before. the closest thing to it I can recall is when you have a part from the assembly open in another window and are editing a sketch. You can switch to the assembly document, but you can't select anything or change the view. I've also seen something like this when you're in large-design-review mode (which you aren't),
The only thing I can think of is that it's related to your mouse software-that you've got some kind of logitech scroll lock enabled and it's trapping your mouse in a state that won't allow it to go into selection mode. If this were the case, you'd have this problem in applications other than Solidworks.
Finally, since you're running a Chinese langauge (or is it Korean) version, you might be looking at a localization bug.
You're running Solidworks 2011. What service pack do you have applied.
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