cannot install SuiteCRM 7.8.9

Hi all,

I just downloaded SuiteCRM 7.8.9 and stuck on installation.
Step 1 is OK.

Step 2 is nightmare

As SuiteCRM Database User I put root which has no password.
I checked twice that I can login PhpMyAdmin as root without password.

But I always have same error
[color=#ff0000]The provided database host, username, and/or password is invalid, and a connection to the database could not be established. Please enter a valid host, username and password[/color]

Please explain me why.