Gmpublish update Assertion error

Can someone explain why this is happening?

C:\Program Files (x86)\Steam\SteamApps\common\Half-Life 2\ep2\maps\gmod workshop
>gmpublish update -addon “C:\Program Files (x86)\Steam\SteamApps\common\Half-Lif
e 2\ep2\maps\gmod workshop\gm_ghosthunt_3.gma” -id “403872634”
Garry’s Workshop Publisher 1.0
[Compiled Jun 8 2014 - 17:16:08]
Setting breakpad minidump AppID = 4000
Steam_SetMinidumpSteamID: Caching Steam ID: 76561197963316039 [API loaded no]
Compressing… [35.2 MB] => [15.3 MB]
Updating Addon…
Committing… (this can take a long time)
… ier1\fileio.cpp (4002) : Assertion Failed: m_nNumRegisteredWriters == 0
Assert( Assertion Failed: m_nNumRegisteredWriters == 0 ):… ier1\fileio.cpp:400

It’s Steam, don’t worry, it doesn’t affect anything.

So it’ll pass? Would like to update my addon is all

EDIT: - Seems to have gone through, sorry! Thank you for the response though.