Sabertooth z77 and cpu fan error

i just completed assembly of my new rig.
as the thread title suggests, i am using a asus z77 sabertooth and a 212 evo hsf.

when i first tested the mobo and other core components, everything was fine except i received a 'cpu fan error.'
the cpu fan error persisted throughout the windows installation in which i had to manually boot from bios.
after i installed the most updated bios chipset drivers the error stopped appearing.
i should mention that the cpu fan had always been running even when the error appeared.
i checked the cpu temp (i7 3770k) with a monitor program and the cpu core temps range from about 22-28c (not under load and not overclocked) so everything appears to be ok.

should i just forget about it since the error stopped appearing or is there more investigation i need to do on the matter? this is probably a dumb question as the error is no longer showing but i would just like to know to be safe as this is the first rig i put together myself in about 12 years.
what caused this error to appear in the first place?

UPDATE:
i had to move my computer so i shut it down, moved it, turned back on and now im getting the cpu fan error again. prior to this i had restarted multiple times without incident (since the chipset driver update anyway). the only difference this time was that i completely shut the computer down. in bios my cpu fan is running in the 590s (shown in red) and goes back and forth between 590s and 600 (when it hits 600+ this is turned to blue, not red). i also noticed that my other chassis fans are running in the 500s for rpm (on my thor v2). right now im guessing that the cpu fan error occurs when the fan is below 600 but i really dont know, this is just a guess. my temps are fine so im not concerned so much about the low rpms for now but i am concerned about the cpu fan error showing every time i want to boot up my computer. this requires me to go into bios and manually boot. will the low rpms on my chassis fans be an issue?