These policies might spit out errors in authpolicyd.

UsbDetachableWhitelist (JSON)
DeviceOffHours (JSON)
TPMFirmwareUpdateSettings (JSON)
DeviceUpdateAllowedConnectionTypes (string->enum conversion)

See device_policy_encoder.cc. There's no way to report that in Chrome right now. The errors would probably have to be stored in the device policy proto, saved to disk in Session Manager, read back by Chrome and pushed to the policy error map. Would be nice if it could be translated as well.