Error: Unable to load TALPA modules. On access scan is not enabled/running.

If you are running an unsupported RHEL/Centos distro you can get Sophos talpa modules enabled by installing the kernel modules to allow compilation.

yum install kernel-devel-`uname -r`

Then select the talpa modules again to build them

/opt/sophos-av/engine/talpa_select select

Also check on access scanning is enabled and running and start if not

/opt/sophos-av/bin/savdctl enable
service sav-protect status (Sophos Anti-Virus daemon is active)
/opt/sophos-av/bin/savdstatus (Sophos Anti-Virus is active and on-access scanning is running)

Check that AV is updated

/opt/sophos-av/bin/savupdate (Successfully updated Sophos Anti-Virus from sdds:SOPHOS)

Everything else should be configurable from Sophos Central