I'm having problems with this particular system update. The update failed during "Checking data integrity..." with this message:
An error occurred while downloading. Please check your connection or try again later.
There's nothing wrong with my internet connection.
The update will fail at this spot again in subsequent update attempts. It seems like during the subsequent tries, it does not re-download the update package, as the progress indicator will immediately display "Checking data integrity..." again.
I'm using the AMD64 version of PC-BSD 8.1.