I have download ADT 21.1, and tried install it on eclipse
I got those:
The operation cannot be completed. See the details.
Details:
Cannot complete the request. See the error log for details.
Tracer for OpenGL ES will be ignored because it is already installed, and updates are not permitted.
Android DDMS will be ignored because it is already installed, and updates are not permitted.
Android Development Tools will be ignored because it is already installed, and updates are not permitted.
Android Traceview will be ignored because it is already installed, and updates are not permitted.
Android Hierarchy Viewer will be ignored because it is already installed, and updates are not permitted.
When I reopen SDK Manager, I still got this:
In Windows->Preference->Android, I got this:
Thus, I wanna reintall ADT, but I found I can't uninstall any Plug In, Uninstall.. button is gray!