RB750r2 Hex Lite User manager installation

Hi to all! I need your help on installing the user manager for my hotspot setup. I uploaded the user-manager-6.32.1-mipsbe.npk file in the RB but when I restarted I cannot find it in the packages but the file is still in files.

Can you please check how many left hdd space there is available?

Total HDD size = 16MB Free HDD space = 3896KB