Today ,I work in the company and I solve the sdk manager:error null.First, I want to tell you that I am a freshman.In the company,we develop on the Ubuntu Linux System and develop the Android app for ourselves cell phone.When I built the android development environment ,there is a error :sdk manager:error null.I try my best to find and solve the problem.First,I check the .bashrc file,because I want to confirm the sdk path is correct.Of cause ,it does.For a long time ,I find a link under the /home path,which is .android -> /local/.android ,and there isn't the /local/.android file,so I delete the link and restart the Eclipse.It works.haha