failure: database is corrupted or out of disk space

What can I do with this warning?

failure: database is corrupted or out of disk space

I’m not able to login to the userman.

paste this on terminal

/tool user-manager database
clear-log
y
rebuild
y
/tool user-manager log remove [find]
/tool user-manager session remove [find]
/tool user-manager database
rebuild
y
/system reboot
y

file does not exists.
So what is wrong?

Use my guide:
http://forum.mikrotik.com/t/ros-6-10-user-manager-log-file-has-been-lost/74744/2

Thanks a lot rextended you saved me.

The error on the database caused a dangerous thing the RB has reset the admin password and was able to access with admin - empty