One of the issues with Eclipse: Selected items-> (right) build path->configure the label button on the right side of build path is not visible

Background: It is not known for any reason that the ability to add a jar package was found on build path. At the beginning, directly select the Item right button to add on it. But today, two jars were added, and the result was an error, because I accidentally clipped the jar to another folder. And the direct remove is not good. Really can not, simply, see if you can put the right button out, may be deleted or maybe.

As shown in figure:

(right) Build path->configure the label button to the right of the build path does not see the ">

Click on the right side of the "Order and Export" tab, click OK. That's good.

Then we see the libraries and we see the button on the right.

I am not very clear about the specific reasons, and there is a problem, is the order and export right button hour ...

And the second magical place, click on the "Libraries" tab, and then click OK, Order and export restored again, but libraries disappeared again ...

This really is penny Wise lost the watermelon ... But just ignore it. Because the buttons for the order and export labels are basically not available. Just use it first. Don't be too tangled up. The key is to solve the problem.