Is it only me who gets screwed up by such silly little things?
Last night I was working on an Android app. I connect it to a URL. It always threw exception. I scratched my head for one whole hour to find out that Cellular Data was not turned ON on the emulator. 😛

No you are not alone, had a similar thing Happen to me to today.
Tried to build a project with Jenkins but IT always returned an error. After nearly 12 h of trying everything I finally realised that there were Files, which should Not be there, After deleting them IT worked like it did before.