r0zzz

Actually,

when I hit “upload photo” on admin’s user profile, nothing show up even the window to upload photo

was because I forgot to deactivate aplugin “Front-end Editor”.(It seems UM is not compatible with this plugin).

But I sill have problem that users can not upload profile photos, and
Yes, the image I am trying to upload does match the specifications (px&bytes sizes).
I’m not so sure what you mean by

have you granted the user role permissions to upload photos

.
I don’t find any setting menu to disable avatar uploads on UM.