Dedicated server error related math lua library

#Console initialized.
#FileSystem_LoadSearchPaths
#ConVarRef mat_dxlevel doesn't point to an existing ConVar
#Game.dll loaded for "Garry's Mod"
Initializing Steam libraries for Workshop..
WS: No +host_workshop_collection or it is invalid!
Network: IP 192.168.88.254, mode MP, dedicated Yes, ports 27015 SV / 27005 CL
Error loading cfg/trusted_keys_base.txt
Error loading cfg/pure_server_minimal.txt
PREP OK

[ERROR] Couldn't include file 'math\ease.lua' - File not found (@lua/includes/extensions/math.lua (line 2))
  1. unknown - lua/includes/extensions/math.lua:2
   2. include - [C]:-1
    3. unknown - lua/includes/init.lua:102

This is the beggining of the console log. Never had the issue, maybe someone came across the same thing? Also as it could be useful information, it is on x86-64 dedicated server branch.
It looks like it is missing lua file but couldn’t determine what exactly is it for but my guess is:

This is now fixed: Garrys Mod/main/chromium/go#8400 - Facepunch Commits
Update your server.

Nope, the error still persists, beside it was already newest version, I have even redownloaded the server but no luck.

You can still then retrieve the file from the GitHub repository, the fix seems to be only for clients maybe.

The file is even missing on client on x86-64 branch.

Yes because it will be included in the next update. The fix prevents the creation of an additional entry in the send.txt file (if not already done). This also goes for dedicated servers.