Whenever I enable the OSVR plugin in UE4.12, the editor will crash on start. I saw this post which says this bug was fixed in preview 5, but I am having the same issue on the release version of 4.12.
Here is the crash report
Unknown exception - code c06d007e (first/second chance not available)
KERNELBASE
UE4Editor_OSVR!_delayLoadHelper2()
UE4Editor_OSVR!_tailMerge_osvrClientKit_dll()
UE4Editor_OSVR!OSVREntryPoint::OSVREntryPoint()
UE4Editor_OSVR!FOSVR::StartupModule()
UE4Editor_Core!FModuleManager::LoadModuleWithFailureReason() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\modules\modulemanager.cpp:480]
UE4Editor_Projects!FModuleDescriptor::LoadModulesForPhase() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\projects\private\moduledescriptor.cpp:398]
UE4Editor_Projects!FPluginManager::LoadModulesForEnabledPlugins() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\projects\private\pluginmanager.cpp:540]
UE4Editor!FEngineLoop::LoadStartupModules() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:2155]
UE4Editor!FEngineLoop::PreInit() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:1609]
UE4Editor!GuardedMain() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\launch.cpp:114]
UE4Editor!GuardedMainWrapper() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:200]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264]
kernel32
ntdll