As pointed out in this thread the error is a proprietary error message generated by the firmware's WMI object.
According to this bug report there is a workaround at least for ubuntu:
"For those with this same toshiba satellite L15W-Bxxx and have constant freezing,
I have a work around for you.
sudo nano -w /etc/default/grub
pass these kernel arguments:
GRUB_CMDLINE_LINUX_DEFAULT="acpi_osi=Linux acpi_call intel_idle.max_cstate=1 intel_pstate=enable video=i915"
well, the most important two is intel_idle.max_cstate=1 intel_pstate=enable
intel_idle.max_cstate=1 will allow your baytrail processor to idle, some reason the kernel doesn't know how to idle the CPU properly so it runs on full speed at all times, and bursting to its turbo speed under load hastens the overheating, with no way to keep the core cool, even when there is nothing really running, just ends with a frustrating hard lock, and resetting the power is the only way to recover, but there is nothing in the dmesg, kern.log, fail.log, etc. using MCE logs, it only says a thermal hardware event occurred.
intel_pstate=enable this will allow you to set scaling frequency using thermald, sensor and tlp, (several guides on how to set these up, I can't sensors and pwm to detect any fans so if anyone has figured that out, let us know), but with these packages, my processor, when nothing intensive is going on it can scale between 500mhz to 2.16ghz on battery, and 1.5ghz-2.6ghz with ac in, and is able to shut down cores as need be as well. I set powersave mode for when its running on battery and performance mode when ac is plugged in.... I have not had a single issue with lock up and freezing anymore. So that ended my 6 months of frustration.
But I still get "toshiba_acpi: Unknown event received 93" nonstop, but now my system isn't freezing within 15-180 minutes after bootup anymore, in that regard i'm pretty stoked."