pg_ctl promote causes error "could not read block" (PG 9.5.0 and 9.5.4)

Hi there,

we are running into this weird issue of table getting on READ ONLY mode
with below error:

ERROR: could not read block 54 in file "base/<databaseoid>/215619": read
only 0 of 8192 bytes

We are facing this whenever we promote a streaming standby using pg_ctl
promote command, and this is happing on PG 9.5.0 and 9.5.4 and OEL 6.9

Are we hitting some bug? tried to look around but not able to confirm if we
are hitting a bug or not. For us this is happening consistently on
different servers whenever we do pg_ctl promote and then it block WRITE on
that table.

As of now we get rid of the error either by doing vacuum full or CTAS, but
i am afraid what we will do in case this happens to our few TB tables.

Thanks a lot in advance

-raj