Hello friends,
I have this problem with an RB2011il. I have deleted admin user, and have created another user with different name with full privileges and different password.
I open winbox, i see my router with it's ip address but when i try to connect with ip and username/pass i get error: Wrong username or password. The only way i can login is by mac address.
The same thing happens when trying to login from web interface.
Does anyone know something about it?

When you connect by IP you get wrong password but with Mac no problem? Maybe the error is "could not connect" ?
I' ve never seen anything similar.
If your username and password are correct it will login by MAC and IP.
I Guess you can't login by IP because of wrong configuration...
Whar is your IP and what is the router's IP ?

Zacharias thanks for your reply,
All this happens when i am locally connected to router. When you use mac address it connects automatically. When i try to connect with the ip let's say 10.x.x.1 i get the error: Wrong username or password. Even though i am in the same network with router.
The username and password are correct because i myself created them. The configuration is correct and there is nothing like a firewall rule to do this.
The same thing happens when i try to connect remotely to the router.

What is your RouterOs version ?
Is your IP in the same subnet as the router's IP ?
Winbox version ?

RouterOS version is 6.45.6 mipsbe
Yes as i said i try locally to connect from the same subnet as the router's ip.
Winbox version is 3.18
The same happens in another router rb2011L with 6.43.11 OS version.

Update winbox to 3.19 and try again...

I did that but nothing happened still the same problem!!!

Are you able to connect via Telnet if you re-create admin user with full access?
If you are not able to connect with the newest winbox version, problem could be in the configuration.

kristsd i will try to hard reset and just re-create user admin with my own password and no configuration at all and see what will happen.
It is very strange behaviour!!!!

kristsd i will try to hard reset and just re-create user admin with my own password and no configuration at all and see what will happen.
It is very strange behaviour!!!!

Without a configuration you woun't be able to connect through IP telnet.. only MAC telnet.

I meant without any other configuration - firewall or something else.I have an ip in the same subnet but the problem remains!!!!!!

I meant without any other configuration - firewall or something else.I have an ip in the same subnet but the problem remains!!!!!!

When you connect via MAC telnet to the device -
Are you able to ping the IP from the subnet IP you have given to the device you are not able to connect via IP telnet?

kristsd yes i can ping just fine.
The only thing i haven't tried yet is to rollback to previous OS version with net install and try again, but i don't have time to do it!!!
I have configured many mikrotik routers but this is the first time that i can't connect using a username and password that i have created!!!!! Remotely or locally from the same network.

Guys after hard reset and net install with latest version OS it came around and everything is fine now.