在特定情况下，鼠标点击.uproject文件右键菜单消失。
会造成比如：
无法手动生成VisualStudioProjectFiles。
无法切换UE4各个版本，从而导致版本错开崩溃、每次开启项目自动生成格外副本工程 等问题。
搜遍了全网+自己实验，总结解决方法如下：
一、被win10默认防护、其他杀毒软件删除
关闭/卸载杀毒软件、关闭win10防护
以win10防护为例，打开 windows安全中心，
分别关闭 病毒和威胁防护、防火墙和网络保护、 应用和浏览控制
二、删除注册表，运行CMD
1.删除注册表
1）按下 Ctrl+R 输入 regegit 调出注册表
2）删除 HKEY_CLASSES_ROOT 下的 .uproject文件夹
2.创建cmd并运行重启
新建一个文本文档，然后改名为 UnrealProjectMenuRegistration.cmd，复制如下代码
:: UnrealProjectMenuRegistration.cmd
::
:: This batch file will try to find where the Unreal Engine is installed, then update your registry
:: to register the Unreal Project File type (and its right click menu for things such as generating
:: Visual Studio project files, and launching)
::
:: Run as an Administrator, as it's required for writing to HKLM.
::
:: Author: David Moore <[email protected]>
@ECHO OFF
echo.
echo Locating where Unreal Engine is installed by checking the Windows registry...
::FOR /F "tokens=2*" %%A IN ('reg query "HKLM\SOFTWARE\EpicGames\Unreal Engine" /v "INSTALLDIR"') DO (
:: SET "UnrealEngineDir=%%B"
::)
:: 设置为当前虚幻引擎安装目录
SET UnrealEngineDir=D:\Epic Games\
IF "%UnrealEngineDir%"=="" GOTO CannotFindUnrealEngine
echo.
echo Using Unreal Engine directory: %UnrealEngineDir%
set LauncherPath=%UnrealEngineDir%Launcher\Engine\Binaries\Win64\UnrealVersionSelector.exe
echo.
echo Adding registry keys for the Unreal Project right click menu...
:: HKLM\SOFTWARE\Classes\.uproject
reg ADD "HKLM\Software\Classes\.uproject" /ve /d Unreal.ProjectFile /f
IF ERRORLEVEL 1 (
echo Couldn't write to registry. Did you forget to run this batch file as an administrator?
goto TheEnd
)
:: HKLM\SOFTWARE\Classes\Unreal.ProjectFile
reg ADD "HKLM\Software\Classes\Unreal.ProjectFile" /ve /d "Unreal Engine Project File" /f
:: HKLM\SOFTWARE\Classes\Unreal.ProjectFile\DefaultIcon
reg ADD "HKLM\Software\Classes\Unreal.ProjectFile\DefaultIcon" /ve /d "\"%LauncherPath%\"" /f
:: HKLM\SOFTWARE\Classes\Unreal.ProjectFile\shell\open
reg ADD "HKLM\Software\Classes\Unreal.ProjectFile\shell\open" /ve /d "Open" /f
reg ADD "HKLM\Software\Classes\Unreal.ProjectFile\shell\open\command" /ve /d "\"%LauncherPath%\" /editor \"%%1\"" /f
:: HKLM\SOFTWARE\Classes\Unreal.ProjectFile\shell\run
reg ADD "HKLM\Software\Classes\Unreal.ProjectFile\shell\run" /ve /d "Launch game" /f
reg ADD "HKLM\Software\Classes\Unreal.ProjectFile\shell\run" /v Icon /t REG_SZ /d "\"%LauncherPath%\"" /f
reg ADD "HKLM\Software\Classes\Unreal.ProjectFile\shell\run\command" /ve /d "\"%LauncherPath%\" /game \"%%1\"" /f
:: HKLM\SOFTWARE\Classes\Unreal.ProjectFile\shell\rungenproj
reg ADD "HKLM\Software\Classes\Unreal.ProjectFile\shell\rungenproj" /ve /d "Generate Visual Studio project files" /f
reg ADD "HKLM\Software\Classes\Unreal.ProjectFile\shell\rungenproj" /v Icon /t REG_SZ /d "\"%LauncherPath%\"" /f
reg ADD "HKLM\Software\Classes\Unreal.ProjectFile\shell\rungenproj\command" /ve /d "\"%LauncherPath%\" /projectfiles \"%%1\"" /f
:: HKLM\SOFTWARE\Classes\Unreal.ProjectFile\shell\switchversion
reg ADD "HKLM\Software\Classes\Unreal.ProjectFile\shell\switchversion" /ve /d "Switch Unreal Engine version..." /f
reg ADD "HKLM\Software\Classes\Unreal.ProjectFile\shell\switchversion" /v Icon /t REG_SZ /d "\"%LauncherPath%\"" /f
reg ADD "HKLM\Software\Classes\Unreal.ProjectFile\shell\switchversion\command" /ve /d "\"%LauncherPath%\" /switchversion \"%%1\"" /f
:Done
echo.
echo Done.
echo.
goto TheEnd
:CannotFindUnrealEngine
echo.
echo DOH! Can't find the Unreal Engine.
echo.
goto TheEnd
:TheEnd
pause修改 SET UnrealEngineDir=D:\Epic Games\
修改为Unreal Engine的路径（是UnrealEngine 的路径不是EpicLauncher的）
SET UnrealEngineDir=D:\Epic Games\保存，右键以管理员身份运行，重启电脑即可。
三、重启后运行UnrealVersionSelector.exe
如，方法一、方法二都失效是使用下述方法：
1.找到Epic Game Lancher的安装目录，在lancher->Engine->Binaries->Win64->UnrealVersionSelector.exe
2.把UnrealVersionSelector.exe 分别拷贝到UE4 不同版本引擎的 Engine->Binaries->Win64目录，例如UE_4.25->Engine->Binaries->Win64
3.双击，以管理员身份运行UnrealVersionSelector.exe，重启电脑即可。
四、双击.uproject不能直接打开UE编辑器问题
1.计算机/此电脑 - 属性 - 系统属性 - 环境变量
2.新增一个用户环境变量，如下所示：
变量名：OPENSSL_ia32cap
变量值：~0x20000000
保存，即可。