Eclipse:some sites could not be found. See the error log for more detail. Workaround

Today, a wonderful problem has been encountered. I upgraded the version number of my SDK tools to 23. I tried to upgrade ADT in Eclipse and found a problem with the following analysis for the reasons below:

When I select Help-->check for updates in Eclipse. A box will pop up. For example, the following:

First, explain why this error occurred :

When eclipse is check for updates, it is based on all available software sites in the list.

When there is a site that does not exist. The error will occur.

Someone here might ask, I used to install the address can be used, why now the address is not. This is because some plug-in's site address is in fact not static.

Workaround : Place the non-existent address indicated in the first image. Find in the list of the second image, and remove the tick from the front of the non-existent address. Check for updates again at this time.

Eclipse:some sites could not be found. See the error log for more detail. Workaround