Cannot log in as admin

Hi

I have downloaded the Nexus repo successfully on my Ubuntu and I cannot log in with my credentials. I am entering the correct log in details in the respective fields but i keep getting an error message ’ Incorrect username or password, or no permission to use the application.’

I have also tried different browser? I used the donwload link from sonatype, am i doing anything wrong?

regards

Did you change the initial administrator password to something else?

No password change has been attempted . Still trying to log in using the random password that was generated.