V8JsEngine Issue

Hi, I’m trying to start the bot for the first time and i’m getting this issue just after clicking to start a session. I googled parts of the report but idk how to use nuget or stuff like that.

I’m using win 7 profesional in a vmware machine if that’s important.

I’m missing something in the istallation? what should I do to make it work?

Srry if I have not give all the important info, I’m really new to this world

`
Failed to start play session:
Failed to prepare Elm app process: System.AggregateException: One or more errors occurred. (Failed to create instance of the V8JsEngine. Most likely it happened, because the 'ClearScriptV8.win-x64.dll' assembly or one of its dependencies was not found. Try to install the Microsoft.ClearScript.V8.Native.win-x64 package via NuGet.)
 ---> JavaScriptEngineSwitcher.Core.JsEngineLoadException: Failed to create instance of the V8JsEngine. Most likely it happened, because the 'ClearScriptV8.win-x64.dll' assembly or one of its dependencies was not found. Try to install the Microsoft.ClearScript.V8.Native.win-x64 package via NuGet.

Engine name: V8JsEngine
Engine version: 9.8.177.9
Category: Engine load error
Description: Most likely it happened, because the 'ClearScriptV8.win-x64.dll' assembly or one of its dependencies was not found. Try to install the Microsoft.ClearScript.V8.Native.win-x64 package via NuGet. ---> System.TypeLoadException: Cannot load ClearScript V8 library. Load failure information for ClearScriptV8.win-x64.dll:
C:\Users\Juan\AppData\Local\Temp\.net\BotLab\wP8xDurm48L1VoDozN0SrIJpv4n_oIY=\runtimes\win-x64\native\ClearScriptV8.win-x64.dll: Dll was not found.
C:\Users\Juan\AppData\Local\Temp\.net\BotLab\wP8xDurm48L1VoDozN0SrIJpv4n_oIY=\ClearScriptV8.win-x64.dll: Dll was not found.
C:\Windows\system32\ClearScriptV8.win-x64.dll: Dll was not found.
   at Microsoft.ClearScript.V8.V8Proxy.LoadNativeLibrary(String baseName, String platform, String architecture, String extension)
   at Microsoft.ClearScript.V8.V8Proxy.LoadNativeAssembly()
   at Microsoft.ClearScript.V8.V8Proxy.OnEntityHolderCreated()
   at Microsoft.ClearScript.V8.SplitProxy.V8IsolateProxyImpl..ctor(String name, V8RuntimeConstraints constraints, V8RuntimeFlags flags, Int32 debugPort)
   at Microsoft.ClearScript.V8.V8Runtime..ctor(String name, V8RuntimeConstraints constraints, V8RuntimeFlags flags, Int32 debugPort)
   at Microsoft.ClearScript.V8.V8ScriptEngine..ctor(V8Runtime runtime, String name, V8RuntimeConstraints constraints, V8ScriptEngineFlags flags, Int32 debugPort)
   at Microsoft.ClearScript.V8.V8ScriptEngine..ctor(V8RuntimeConstraints constraints, V8ScriptEngineFlags flags, Int32 debugPort)
   at JavaScriptEngineSwitcher.V8.V8JsEngine..ctor(V8Settings settings)
   at JavaScriptEngineSwitcher.V8.V8JsEngine..ctor(V8Settings settings)
   at ElmFullstack.ProcessHostedWithV8.ConstructJsEngine()
   at ElmFullstack.ElmAppCompilation.CreateJsEngineToCompileFileTree(IImmutableDictionary`2 compilerElmProgramCodeFiles)
   at ElmFullstack.ElmAppCompilation.<>c__DisplayClass15_0.<CachedJsEngineToCompileFileTree>b__0(String _)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
   at ElmFullstack.ElmAppCompilation.CachedJsEngineToCompileFileTree(IImmutableDictionary`2 compilerElmProgramCodeFiles)
   at BotLab.Client.ProgramCodeModel.BotProgramCode.ElmAppCompilation(IImmutableDictionary`2 compilerElmProgramCodeFiles, IImmutableDictionary`2 sourceFiles, IImmutableList`1 rootModuleName, IImmutableList`1 interfaceToHostRootModuleName, ImmutableList`1 dependencies)
   at BotLab.Client.ProgramCodeModel.BotProgramCode.GetLoweredProgramCodeToRun(TreeWithStringPath originalProgramCodeTree)
   at BotLab.Client.PlaySession.<>c__DisplayClass62_0.<PrepareRun>b__0()
   at System.Threading.Tasks.Task`1.InnerInvoke()
   at System.Threading.Tasks.Task.<>c.<.cctor>b__272_0(Object obj)
   at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
   at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)

   --- End of inner exception stack trace ---
   at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
   at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
   at System.Threading.Tasks.Task`1.get_Result()
   at BotLab.Client.PlaySession.PrepareRun(PreparedPlaySessionBuildingProcess preparedPlaySessionBuildingProcess, IConsoleUserInterface userInterface)
`

Welcome Yagus :wave:

I do not remember seeing such an error before.

You certainly don’t need to use NuGet or anything else to get the V8JsEngine separately, as it comes packaged with the botlab executable file.

There is no installation necessary. You can even just run the botlab.exe and skip installation.

That setup you describe here is very unusual because it uses Windows 7. It might be simply that the V8JsEngine part of the whole program does not work on Windows 7.

Windows 7 is generally out of support at Microsoft since 2020.

I recommend running it on Windows 10 to avoid this error.

I remade my vms with win 10 and all is working.
Ty for your quick answer and solution.

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