These two errors are probably more important to fix given how many plugins depend on tf2_stocks.
C:\tf2_server\tf\addons\sourcemod\scripting\i nclude\tf2_stocks.inc(331) : error 009: invalid array size (negative, zero or out of bounds)
C:\tf2_server\tf\addons\sourcemod\scripting\i nclude\tf2_stocks.inc(351) : error 010: invalid function or declaration
However, trying to fix cURL, socket and SteamWorks is just opening a larger can of worms. I assume someone who knew what they were doing could knock this out briefly but sadly I don't.
cURL.inc -
https://pastebin.com/ZgVEd5hQ
socket.inc -
https://pastebin.com/MW66KYkm
SteamWorks.inc -
https://pastebin.com/TR9p8z9U
Code:
C:\tf2_server\tf\addons\sourcemod\scripting>spcomp updater
SourcePawn Compiler 1.11.0.6570
Copyright (c) 1997-2006 ITB CompuPhase
Copyright (c) 2004-2018 AlliedModders LLC
C:\tf2_server\tf\addons\sourcemod\scripting\include\cURL.inc(168) : error 139: could not find type "last_sent_dataSize"
C:\tf2_server\tf\addons\sourcemod\scripting\include\cURL.inc(169) : error 139: could not find type "last_sent_dataSize"
C:\tf2_server\tf\addons\sourcemod\scripting\include\cURL.inc(182) : error 139: could not find type "dataSize"
C:\tf2_server\tf\addons\sourcemod\scripting\include\cURL.inc(183) : error 139: could not find type "dataSize"
C:\tf2_server\tf\addons\sourcemod\scripting\include\cURL.inc(203) : error 139: could not find type "bytes"
C:\tf2_server\tf\addons\sourcemod\scripting\include\cURL.inc(203) : error 139: could not find type "nmemb"
C:\tf2_server\tf\addons\sourcemod\scripting\include\cURL.inc(204) : error 139: could not find type "bytes"
C:\tf2_server\tf\addons\sourcemod\scripting\include\cURL.inc(204) : error 139: could not find type "nmemb"
C:\tf2_server\tf\addons\sourcemod\scripting\include\cURL.inc(207) : error 139: could not find type "bytes"
C:\tf2_server\tf\addons\sourcemod\scripting\include\cURL.inc(207) : error 139: could not find type "nmemb"
C:\tf2_server\tf\addons\sourcemod\scripting\include\cURL.inc(208) : error 139: could not find type "bytes"
C:\tf2_server\tf\addons\sourcemod\scripting\include\cURL.inc(208) : error 139: could not find type "nmemb"
C:\tf2_server\tf\addons\sourcemod\scripting\include\socket.inc(221) : error 139: could not find type "remotePort"
C:\tf2_server\tf\addons\sourcemod\scripting\include\socket.inc(240) : error 139: could not find type "dataSize"
C:\tf2_server\tf\addons\sourcemod\scripting\include\socket.inc(282) : error 139: could not find type "errorType"
C:\tf2_server\tf\addons\sourcemod\scripting\include\socket.inc(282) : error 139: could not find type "errorNum"
updater/plugins.sp(41) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/plugins.sp(41) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/plugins.sp(55) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/plugins.sp(55) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/plugins.sp(84) : warning 213: tag mismatch (expected "int", got "DataPackPos")
updater/plugins.sp(87) : warning 213: tag mismatch (expected "int", got "DataPackPos")
updater/plugins.sp(90) : warning 213: tag mismatch (expected "int", got "DataPackPos")
updater/plugins.sp(93) : warning 213: tag mismatch (expected "int", got "DataPackPos")
updater/plugins.sp(128) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/plugins.sp(128) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/plugins.sp(135) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/plugins.sp(135) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/plugins.sp(142) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/plugins.sp(142) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/plugins.sp(149) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/plugins.sp(149) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/plugins.sp(156) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/plugins.sp(156) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/download_socket.sp(41) : warning 213: tag mismatch (expected "int", got "DataPackPos")
updater/download_socket.sp(44) : warning 213: tag mismatch (expected "int", got "DataPackPos")
updater/download_socket.sp(47) : warning 213: tag mismatch (expected "int", got "DataPackPos")
updater/download_socket.sp(50) : warning 213: tag mismatch (expected "int", got "DataPackPos")
updater/download_socket.sp(62) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/download_socket.sp(62) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/download_socket.sp(73) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/download_socket.sp(73) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/download_socket.sp(104) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/download_socket.sp(104) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/download_socket.sp(134) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/download_socket.sp(134) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/download_socket.sp(161) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/download_socket.sp(161) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/download_socket.sp(166) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/download_socket.sp(166) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/download_socket.sp(193) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/download_socket.sp(193) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/download_steamworks.sp(12) : error 017: undefined symbol "SteamWorks_CreateHTTPRequest"
updater/download_steamworks.sp(13) : error 017: undefined symbol "SteamWorks_SetHTTPRequestHeaderValue"
updater/download_steamworks.sp(14) : error 017: undefined symbol "SteamWorks_SetHTTPRequestHeaderValue"
updater/download_steamworks.sp(15) : error 017: undefined symbol "SteamWorks_SetHTTPCallbacks"
updater/download_steamworks.sp(16) : error 017: undefined symbol "SteamWorks_SetHTTPRequestContextValue"
updater/download_steamworks.sp(17) : error 017: undefined symbol "SteamWorks_SendHTTPRequest"
updater/download_steamworks.sp(27) : error 017: undefined symbol "k_EHTTPStatusCode200OK"
updater/download_steamworks.sp(29) : error 017: undefined symbol "SteamWorks_WriteHTTPResponseBodyToFile"
updater/download.sp(64) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/download.sp(64) : warning 213: tag mismatch (expected "DataPackPos", got "int")
updater/download.sp(70) : error 017: undefined symbol "STEAMWORKS_AVAILABLE"
updater/download.sp(83) : error 017: undefined symbol "STEAMWORKS_AVAILABLE"
Compilation aborted.
26 Errors.