Persist error when serializing a thread

[Morcar_Leofricson]

When I create a thread, for example like this:

CreateGameTimeThread(function()
    Sleep(const.DayDuration)
    -- Do something
end)

If I save the game while the thread is running I find a "Persist error" in the log:

Spoiler: Log

Persist error: Attempt to persist a C function
Persist stack:
table: 000001A68057B830
table: 000001A680A85460
table: 000001A681B904E8
cthreads.threads
table: 000001A681B90528
thread: 000001A6848F7BA0
function: 000001A6809C1F40
table: 000001A6827122E8
rawget
function: 000001A6803B1290
function: 00007FF7D32E1400

Does anyone knows anything about this? Am I doing something wrong? Is it a bug? Can I safely ignore these errors?
Any help would be appreciated.

 

[ChoGGi_2]

It's less an error and more a warning (it won't hurt anything).

 

[Morcar_Leofricson]

Thanks for your reply.
They should have made their warnings more explicit.