Anyone else having this issue?

I asked Xanaguy, and he isn't sure why that is happening, since we've never had these errors on our end.

Make sure your server is supporting the correct, and most up-to-date version of the map, otherwise it will cause issues.

I went ahead and scoured the internet a bit, these links might provide useful:
https://psteamcommunity.yuanyoumao.com/groups/MGFTW/announcements/detail/1621579134207782419

引用自 MGFTW：

A lot of players seem to get the error:
Host_Error: CMapLoadHelper::Init, unable to open maps/<mapname> when they try to join the custom maps server.

The reason for this is the terrible way in which Steam Workshop handles addons. If you launch L4D2 you can see an animated circle left from the addons menu option which means it's processing all your workshop addons.
At that time your addons are not available yet so if you join the custom map server before it's ready it throws out that error message and crashes your game.

To work around this, wait for the addon process to complete (circle disappears) then join the server.

https://forums.alliedmods.net/showthread.php?t=156313

引用自 Bacardi：

What I have found is something to do [with] ... left4dead/addonlist.txt

引用自 KawMAN：

Put vpk to addons folder and in left4dead/addonlist.txt add
Code:
Code:
"deadline.vpk" "1"
exapmle:
Code:
"AddonList"
{
"deadline.vpk" "1"
"deathaboard.vpk" "1"
"orange" "1"
"warehouse23.vpk" "1"
}
And edit addonlist.txt properties to "Read only" or chmod 444 that server not rewrite taht file.

Try these

*edit
Didin't know that *.vpk files go ...addons/ folder

I hope that will help, otherwise it might be worth asking on Alliedmodder[forums.alliedmods.net] for help.

Doesn't work on my dedicated server either. Server works fine normal maps or some game of thrones map i tested with. Game never starts as it can't find a server with the map.

Edit: Just noticed that it still has serious_samurais MOTD on my server. Deleted the dedicated server dir, and it's still there after re-install. How the hell do i get rid of that?

Edit #2: Deleted my HKEY_CURRENT_USER\SOFTWARE\Valve key in registry, and deleted all SteamCMD and dedicated server folders. Reinstalled everything from scratch, and now i can join my dedicated with the new Helms Deep Fixed map \o/

引用自 Sirro：

Anyone else having this issue?

Yes : ((
Funny thing is, I found:
Host_Error: CMapLoadHelper::Init, unable to open maps/map_name.bsp

You don't have the *.vpk file installed in the addons folder.
If you do, it means the custom map is disabled in the L4D2 main menu addons list.

the above is not complete, I have the addon installed and it is enabled.
I copied the vpk + the jpg to the dedicated server

I can start from l4d2 a local server and this will start the map fine

when I either start the dedicated server with the map or use !admin to switch map, both ways, same error : ((

As a local server this seems to work:
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2987986639

Will be tested @ NEXTLAN