goodday
recently upgraded my RB951G-2HnD to 6,20, i cant logging into my usermanger "invalid username or password. can someone help? 
I have the same problem.
I upgraded from x86 6.12 to 6.20.
This needs to get fixed soon.
/tool user-manager database> load name=Database.umb
Restore user-manager database? [y/N]:
y
Loading user-manager database backup
Failed to load user-manager database backup
failed to open file for writing: No such file or directory
/file print
NAME TYPE SIZE CREATION-TIME
0 log.0.txt .txt file 118.6KiB oct/13/2014 10:24:51
1 disk1 disk oct/06/2014 17:15:25
2 skins directory may/27/2012 10:16:10
3 Database.umb userman backup 9.1MiB oct/13/2014 10:23:18
4 web-proxy1 web-proxy store may/28/2012 06:26:29
5 pub directory may/28/2012 06:26:29
6 user-manager1 user-manager store oct/06/2014 10:48:20
User Manager is not working at all.
where are the mikrotik geniuses,to solve this