Start Server Failing

Whenever I do Start Server on Roblox Studio none of the Players join and the Server output is filled with WaitForChild infinite yields. This started ever since the WaitForChild update was released.

[details=Error(s)]14:53:28.164 - ! Joining game '00000000-0000-0000-0000-000000000000' place 0 at localhost 14:53:28.166 - Connecting to localhost:53640 14:53:32.596 - Infinite yield possible on 'Workspace:WaitForChild("Terrain")' 14:53:32.598 - Stack Begin 14:53:32.599 - Script 'Plugin_-1.Terrain Tools.TerrainBrushScript', Line 4 14:53:32.601 - Stack End 14:53:32.679 - Infinite yield possible on 'Workspace:WaitForChild("Terrain")' 14:53:32.680 - Stack Begin 14:53:32.681 - Script 'C:/Users/Munim_2/AppData/Local/Roblox/Versions/version-199f4d3921ca4801/BuiltInPlugins/terrain/00 - terrain.lua', Line 24 14:53:32.681 - Stack End 14:53:32.703 - Infinite yield possible on 'Workspace:WaitForChild("Terrain")' 14:53:32.703 - Stack Begin 14:53:32.704 - Script 'C:/Users/Munim_2/AppData/Local/Roblox/Versions/version-199f4d3921ca4801/BuiltInPlugins/terrain/01 - builder.lua', Line 26 14:53:32.705 - Stack End 14:53:32.706 - Infinite yield possible on 'Workspace:WaitForChild("Terrain")' 14:53:32.706 - Stack Begin 14:53:32.707 - Script 'C:/Users/Munim_2/AppData/Local/Roblox/Versions/version-199f4d3921ca4801/BuiltInPlugins/terrain/02 - remover.lua', Line 29 14:53:32.707 - Stack End 14:53:32.712 - Infinite yield possible on 'Workspace:WaitForChild("Terrain")' 14:53:32.712 - Stack Begin 14:53:32.713 - Script 'C:/Users/Munim_2/AppData/Local/Roblox/Versions/version-199f4d3921ca4801/BuiltInPlugins/terrain/03 - elevation.lua', Line 26 14:53:32.713 - Stack End 14:53:32.713 - Infinite yield possible on 'Workspace:WaitForChild("Terrain")' 14:53:32.714 - Stack Begin 14:53:32.714 - Script 'C:/Users/Munim_2/AppData/Local/Roblox/Versions/version-199f4d3921ca4801/BuiltInPlugins/terrain/04 - brush.lua', Line 24 14:53:32.714 - Stack End 14:53:32.715 - Infinite yield possible on 'Workspace:WaitForChild("Terrain")' 14:53:32.715 - Stack Begin 14:53:32.715 - Script 'C:/Users/Munim_2/AppData/Local/Roblox/Versions/version-199f4d3921ca4801/BuiltInPlugins/terrain/06 - craters.lua', Line 25 14:53:32.715 - Stack End 14:53:32.716 - Infinite yield possible on 'Workspace:WaitForChild("Terrain")' 14:53:32.716 - Stack Begin 14:53:32.716 - Script 'C:/Users/Munim_2/AppData/Local/Roblox/Versions/version-199f4d3921ca4801/BuiltInPlugins/terrain/08 - roads.lua', Line 25 14:53:32.716 - Stack End 14:53:32.717 - Infinite yield possible on 'Workspace:WaitForChild("Terrain")' 14:53:32.717 - Stack Begin 14:53:32.717 - Script 'C:/Users/Munim_2/AppData/Local/Roblox/Versions/version-199f4d3921ca4801/BuiltInPlugins/terrain/09 - materialpaint.lua', Line 28 14:53:32.717 - Stack End 14:53:32.718 - Infinite yield possible on 'Workspace:WaitForChild("Terrain")' 14:53:32.718 - Stack Begin 14:53:32.718 - Script 'C:/Users/Munim_2/AppData/Local/Roblox/Versions/version-199f4d3921ca4801/BuiltInPlugins/terrain/10 - stamper.lua', Line 24 14:53:32.718 - Stack End 14:53:32.719 - Infinite yield possible on 'Workspace:WaitForChild("Terrain")' 14:53:32.719 - Stack Begin 14:53:32.720 - Script 'C:/Users/Munim_2/AppData/Local/Roblox/Versions/version-199f4d3921ca4801/BuiltInPlugins/terrain/11 - floodfill.lua', Line 27 14:53:32.720 - Stack End 14:53:33.911 - Infinite yield possible on 'RobloxReplicatedStorage:WaitForChild("SetDialogInUse")' 14:53:33.913 - Stack Begin 14:53:33.914 - Script 'CoreGui.RobloxGui.CoreScripts/MainBotChatScript2', Line 71 14:53:33.915 - Stack End 14:53:34.144 - Infinite yield possible on 'Players.Player:WaitForChild("PlayerGui")' 14:53:34.145 - Stack Begin 14:53:34.146 - Script 'CoreGui.RobloxGui.CoreScripts/Topbar', Line 205 14:53:34.146 - Stack End 14:53:34.146 - Infinite yield possible on 'RobloxReplicatedStorage:WaitForChild("NewFollower")' 14:53:34.150 - Stack Begin 14:53:34.151 - Script 'CoreGui.RobloxGui.CoreScripts/NotificationScript2', Line 439 14:53:34.151 - Stack End 14:53:34.213 - Infinite yield possible on 'RobloxReplicatedStorage:WaitForChild("NewFollower")' 14:53:34.215 - Stack Begin 14:53:34.216 - Script 'CoreGui.RobloxGui.Modules.PlayerDropDown', Line 50 14:53:34.217 - Stack End 14:53:34.279 - Infinite yield possible on 'RobloxReplicatedStorage:WaitForChild("FollowRelationshipChanged")' 14:53:34.280 - Stack Begin 14:53:34.289 - Script 'CoreGui.RobloxGui.Modules.PlayerlistModule', Line 1548 14:53:34.292 - Stack End 14:53:34.548 - Failed to connect to 127.0.0.1|53640. Connection attempt failed
[/details]

I had this output happen once and that was caused by accidentally setting Settings > Network > Diagnostics > IncommingReplicationLag to a really high value (try changing it back to 0 if it’s anything but 0 to make sure that’s not the issue). May also want to check your firewall settings.