[Typo3] Can't login to BE

[Lasse Nørby]

Hi!
I seem to have a problem..
I've made a clean install of testsite 3.8.0 for testing purposes.
My problem is that i am unable to login to the backend.. When I try i says:
"Your login attempt did not succeed. Make sure to spell your username and
password correctly, including upper/lowercase characters."
I've made a new admin user, but this didn't help...
Could it be my php conf, or mysql, or apache or...
Anyone??
Thank you.
Lasse Nørby