Meaning of "There may have been "
Are these sentences correct?. If they are correct what is the meaning of them, please?.

There may have been problems that we don't know about.
There might have been problems that we don't know about.

Question

Meaning of "There may have been "
Are these sentences correct?.  If they are correct what is the meaning of them, please?.

There may have been problems that we don't know about.
There might have been problems that we don't know about.

Answer

They are both correct.  They both mean that the speaker acknowledges the possibility that some person/thing/situation had problems that, for whatever reason, "we" have not discovered.   Example: It was a surprise that Jim and Sally divorced.  They seemed so happy together.  But they may have had problems that we didn't know about.

Answer

I believe it should be rather:  
"There may have been/might have been problems that we DIDN'T know about.
Alternatively:
'There may/might BE problems that we DON'T/ DIDN'T know about.