Trying to resolve another issue (the "maven artifacts not found", which I saw that some other guys here met, but solutions given in their cases didn't work for me) I decided to completely reinstall Android SDK.
So, using Android SDK Manager, I marked all files indicated there and deleted the existing installation. Then I downloaded again all files that it indicated. I only used SDK manager for these operations.
The difference with my previous installation is that, while SDK manager proposes to install in \Program Files\Android, I decided to install everything in c:\Android, (because I saw somewhere in the forum that Erel suggested to someone to do so;perhaps the suggestion was not related to my issue, anyway). Usually I follow defaults when installing, so much probably the previous installation was inside \Program files. Now, as I said, it is in c:\Android. Now, during compilation I get a mysterious "Not found:" nothing, suggesting to use Configure paths..
I managed the Configure Paths as indicated in attached picture.
Anybody knows what happening?
Thanks in advance.