Subscribers cannot access to dashboard – profile page in my website

I’m making a membership website using membership plugin.
and everything worked fine, but I found some problem today.
the problem is that if I log in as ‘subscriber’,
it is impossible to access to dashboard – profile page.
You know subscribers can access to Dashboard that only shows
his/her own profile page. It did work before, but suddenly it doesn’t work.
if I click the toolbar to access either dashboard or profile page,
all I see is this message

“you do not have sufficient permissions to access this page”

but it happens when I log in as subscriber…
if I log in as administrator, everything works fine.
(I haven’t tried other roles so, I’m not sure if other roles can access to profile page or not)

I’m not sure what’s causing this problem at all.
Is there any way to fix this thing?