When I tried to upload a new skin through my minecraft launcher it told me it could not upload and now I can't change or reset my skin. Also I can't join any servers with out getting this error "Internal Exception: java.lang.NullPointerException"

My exact steps were going to www.minecraftskins.com. Typing fbi agent into the search box. Then I downloaded the 4th one in the 4th row. Then, I opened my launcher and selected the skins button. I clicked browse and went into my downloads and then selected the skin. Then I pressed Save.

Any help will be extremely appreciated.