Spam this is the error when connecting or disconnecting players. I reinstalled the server, rolled out the Umod mod without plugins, but still got this error. All ports open.

ArgumentException: name
at System.Net.Http.Headers.HttpHeaders.CheckName (System.String name) [0x00008] in <47ef39777a954e11aa742f58c0c8c611>:0
at System.Net.Http.Headers.HttpHeaders.Add (System.String name, System.Collections.Generic.IEnumerable`1[T] values) [0x0000e] in <47ef39777a954e11aa742f58c0c8c611>:0 77fps 182gc 7h32m46s
at System.Net.Http.Headers.HttpHeaders.Add (System.String name, System.String value) [0x00000] in <47ef39777a954e11aa742f58c0c8c611>:0 5kb/s in, 43kb/s out
at Facepunch.Rust.Analytics+AzureWebInterface.UploadAsync (System.Collections.Generic.List`1[T] records) [0x00191] in <845ba295694a4764887e98a9ada26a7a>:0
UnityEngine.DebugLogHandler:Internal_LogException(Exception, Object)
UnityEngine.DebugLogHandler:LogException(Exception, Object)
UnityEngine.Logger:LogException(Exception, Object)
UnityEngine.Debug:LogException(Exception)
Facepunch.Rust.<UploadAsync>d__17:MoveNext()
System.Runtime.CompilerServices.AsyncTaskMethodBuilder:Start(<UploadAsync>d__17&)
Facepunch.Rust.AzureWebInterface:UploadAsync(List`1)
Facepunch.Rust.<<UploadSchedulingThread>b__0>d:MoveNext()
System.Runtime.CompilerServices.AsyncTaskMethodBuilder:Start(<<UploadSchedulingThread>b__0>d&)
Facepunch.Rust.<>c__DisplayClass15_0:<UploadSchedulingThread>b__0()
System.Threading.Tasks.Task`1:InnerInvoke()
System.Threading.Tasks.Task:Execute()
System.Threading.Tasks.Task:ExecutionContextCallback(Object)
System.Threading.ExecutionContext:RunInternal(ExecutionContext, ContextCallback, Object, Boolean)
System.Threading.ExecutionContext:Run(ExecutionContext, ContextCallback, Object, Boolean)
System.Threading.Tasks.Task:ExecuteWithThreadLocal(Task&)
System.Threading.Tasks.Task:ExecuteEntry(Boolean)
System.Threading.Tasks.Task:System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
System.Threading.ThreadPoolWorkQueue:Dispatch()
System.Threading._ThreadPoolWaitCallback:PerformWaitCallback()