Wadatsumiを動かしていたVPSがリポジトリ壊れたりしておかしくなったので、OS変えて環境を作り直したらOpenSim.exeが起動しなくなりました。
OS：debian9
mono: 5.2.0.215
OpenSimのバイナリーはここでダウンロードできる0.9devです。
エラーの内容は以下のとおりです。
22:57:55 - [DATASNAPSHOT]: Set up snapshot service
Invalid type System.Net.HttpWebRequest for instance field OpenSim.Framework.Communications.RestClient:_request
22:57:55 - [APPLICATION]:
APPLICATION EXCEPTION DETECTED: System.UnhandledExceptionEventArgs
Exception: System.TypeLoadException: OpenSim.Framework.Communications.RestClient
at OpenSim.Region.DataSnapshot.DataSnapshotManager.AddRegion (OpenSim.Region.Framework.Scenes.Scene scene) [0x0009d] in <98de6647a43c427fa6f1d0eb27c48a9a>:0
at OpenSim.ApplicationPlugins.RegionModulesController.RegionModulesControllerPlugin.AddRegionToModules (OpenSim.Region.Framework.Scenes.Scene scene) [0x000ea] in <6fda3b781e9b4b77816fcba1bcdaa285>:0
at OpenSim.OpenSimBase.CreateRegion (OpenSim.Framework.RegionInfo regionInfo, System.Boolean portadd_flag, System.Boolean do_post_init, OpenSim.Framework.IScene& mscene) [0x0012f] in <5ce389e9eeda4b289eaa4a87597e2ee2>:0
at OpenSim.OpenSimBase.CreateRegion (OpenSim.Framework.RegionInfo regionInfo, System.Boolean portadd_flag, OpenSim.Framework.IScene& scene) [0x00001] in <5ce389e9eeda4b289eaa4a87597e2ee2>:0
at OpenSim.ApplicationPlugins.LoadRegions.LoadRegionsPlugin.PostInitialise () [0x00141] in <2e08f80e9762421a8934daab9b8e33ab>:0
at OpenSim.OpenSimBase.StartupSpecific () [0x00213] in <5ce389e9eeda4b289eaa4a87597e2ee2>:0
at OpenSim.OpenSim.StartupSpecific () [0x00120] in <5ce389e9eeda4b289eaa4a87597e2ee2>:0
at OpenSim.Framework.Servers.BaseOpenSimServer.Startup () [0x0006b] in <d7612e8cab064a40a33b455da8d1d877>:0
at OpenSim.Application.Main (System.String[] args) [0x0040a] in <5ce389e9eeda4b289eaa4a87597e2ee2>:0
Application is terminating: True
[ERROR] FATAL UNHANDLED EXCEPTION: System.TypeLoadException: OpenSim.Framework.Communications.RestClient
at OpenSim.Region.DataSnapshot.DataSnapshotManager.AddRegion (OpenSim.Region.Framework.Scenes.Scene scene) [0x0009d] in <98de6647a43c427fa6f1d0eb27c48a9a>:0
at OpenSim.ApplicationPlugins.RegionModulesController.RegionModulesControllerPlugin.AddRegionToModules (OpenSim.Region.Framework.Scenes.Scene scene) [0x000ea] in <6fda3b781e9b4b77816fcba1bcdaa285>:0
at OpenSim.OpenSimBase.CreateRegion (OpenSim.Framework.RegionInfo regionInfo, System.Boolean portadd_flag, System.Boolean do_post_init, OpenSim.Framework.IScene& mscene) [0x0012f] in <5ce389e9eeda4b289eaa4a87597e2ee2>:0
at OpenSim.OpenSimBase.CreateRegion (OpenSim.Framework.RegionInfo regionInfo, System.Boolean portadd_flag, OpenSim.Framework.IScene& scene) [0x00001] in <5ce389e9eeda4b289eaa4a87597e2ee2>:0
at OpenSim.ApplicationPlugins.LoadRegions.LoadRegionsPlugin.PostInitialise () [0x00141] in <2e08f80e9762421a8934daab9b8e33ab>:0
at OpenSim.OpenSimBase.StartupSpecific () [0x00213] in <5ce389e9eeda4b289eaa4a87597e2ee2>:0
at OpenSim.OpenSim.StartupSpecific () [0x00120] in <5ce389e9eeda4b289eaa4a87597e2ee2>:0
at OpenSim.Framework.Servers.BaseOpenSimServer.Startup () [0x0006b] in <d7612e8cab064a40a33b455da8d1d877>:0
at OpenSim.Application.Main (System.String[] args) [0x0040a] in <5ce389e9eeda4b289eaa4a87597e2ee2>:0
exwood@opsim:~/opensim/wadatsumi/OpenSim-0.9.0Dev/bin$ mono --version
Mono JIT compiler version 5.2.0.215 (tarball Mon Aug 14 15:44:25 UTC 2017)
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
TLS: __thread
SIGSEGV: altstack
Notifications: epoll
Architecture: amd64
Disabled: none
Misc: softdebug
LLVM: supported, not enabled.
GC: sgen (concurrent by default)