License Error While Installing Oracle

Greeting,
Can please someone sort out this problem for me.
Mostly when I start performance test for oracle this error appears in different ways like sometimes license not valid, unable to complete test or installation due to license.
Sometimes it works, if I restart my Empirix Application, but mostly it doesn’t work.
A few times. I avoided this error by stopping the session. But yet it doesn’t help me much.
The last action I did was that, I re-installed everything, but again I was suffering with the same error.
I want a perfect solution to this problem.
Can someone please reply to me with a permanent solution to this error?
Thanks.

Error
Connection failed.
License not valid due to problems with dotConnect for Oracle installation.
