Failed to enable the 'dataready' Accept Filter

Looks like your apache httpd is not looking for the httpready Accept Filter, it is looking for dataready filter. I have no idea why. (Wild guess is that your are using mod_ftp.)

try this:

kldload accf_data.ko

or this in loader.conf:

accf_data_load="YES"

For everyone's information, the reason Apache looks for the dataready filter in addition to the httpready filter is because SSL connections cannot be handled with the httpready filter. The dataready filter almost gives the same level of "avoiding-kernel-mode-shifting" benefits to an HTTPS connection.

Do you have accf_data_load="YES" in your loader.conf as well?