oracle express sytem Invalid Login Credentials
I have solved that by doing all the installation and configuration again. I have followed this tutorial: https://forums.oracle.com/forums/thread.jspa?threadID=2301639
my friends, this problem happend when you try connect to localhost:8080/apex/ and over linux, ubuntu or opensuse , if your answer is yes then ,please do it .
Firts login as oracle user: sudo su - oracle .then , read the next steps . on http://mhananto.blogspot.com.co/2012/01/error-invalid-login-credentials-apex-40.html , all credits are to Mr Mahardika Dwi Hananto , thanks for this amazing hack.