Exception during restore #3290

.\.paket\paket.exe : Paket failed with
At line:1 char:1
+ .\.paket\paket.exe install -v 2> install.log
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (Paket failed with:String) [], RemoteException
    + FullyQualifiedErrorId : NativeCommandError
 
-> NotSupportedException: The given path's format is not supported.

   StackTrace:

        at System.Security.Permissions.FileIOPermission.EmulateFileIOPermissionChecks(String fullPath)
        at System.IO.DirectoryInfo.Init(String path, Boolean checkHost)
        at Paket.ProcessHelper.files@17-1.Invoke(String path)
        at Micro
soft.FSharp.Collections.Internal.IEnumerator.map@74.DoMoveNext(b& curr)
        at Microsoft.FSharp.Collections.Internal.IEnumerator.MapEnumerator`1.System-Collections-IEnumerator-MoveNext()
        at Microsoft.FSharp.Collections.Internal.IEnumerator.next@187[T](FSharpFunc`2 f, IEnumerator`1 e, FSharpRef`1 
started, Unit unitVar0)
        at Microsoft.FSharp.Collections.Internal.IEnumerator.filter@182.System-Collections-IEnumerator-MoveNext()
        at Microsoft.FSharp.Collections.SeqModule.oneStepTo@984[T](IEnumerable`1 source, List`1 prefix, FSharpRef`1 
enumeratorR, Int32 i)
        at Microsoft.FSharp.Collections.SeqModule.action@4236-1[T](IEnumerable`1 source, List`1 prefix, FSharpRef`1 
enumeratorR, Int32 i, Unit unitVar0)
        at Microsoft.FSharp.Collections.SeqModule.result@1000.Invoke(Int32 i)
        at Microsoft.FSharp.Collections.Internal.IEnumerator.unfold@199.DoMoveNext(b& curr)
        at Microsoft.FSharp.Collections.Internal.IEnumerator.MapEnumerator`1.System-Collections-IEnumerator-MoveNext()
        at Microsoft.FSharp.Collections.SeqModule.IsEmpty[T](IEnumerable`1 source)
        at Paket.ProcessHelper.tryFindFile(IEnumerable`1 dirs, String file)
        at Paket.NuGetCache.TryGetFallbackFolder()
        at Paket.NuGetCache.TryGetFallbackNupkg(PackageName packageName, SemVerInfo version)
        at Paket.NuGet.getFromFallbackFolder@812(SemVerInfo version, PackageName packageName, String targetFileName, 
Unit unitVar0)
        at Paket.NuGet.download@824-3.Invoke(Unit unitVar)
        at Microsoft.FSharp.Control.AsyncBuilderImpl.callA@522.Invoke(AsyncParams`1 args)
     --- End of stack trace from previous location where exception was thrown ---
        at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
        at Microsoft.FSharp.Control.AsyncBuilderImpl.commit[a](AsyncImplResult`1 res)
        at Microsoft.FSharp.Control.CancellationTokenOps.RunSynchronouslyInCurrentThread[a](CancellationToken token, 
FSharpAsync`1 computation)
        at Microsoft.FSharp.Control.CancellationTokenOps.RunSynchronously[a](CancellationToken token, FSharpAsync`1 
computation, FSharpOption`1 timeout)
        at Microsoft.FSharp.Control.FSharpAsync.RunSynchronously[T](FSharpAsync`1 computation, FSharpOption`1 timeout, 
FSharpOption`1 cancellationToken)
        at Microsoft.FSharp.Collections.Internal.IEnumerator.map@74.DoMoveNext(b& curr)
        at Microsoft.FSharp.Collections.Internal.IEnumerator.MapEnumerator`1.System-Collections-IEnumerator-MoveNext()
        at Microsoft.FSharp.Core.CompilerServices.RuntimeHelpers.takeOuter@274[T,TResult](ConcatEnumerator`2 x, Unit 
unitVar0)
        at Microsoft.FSharp.Core.CompilerServices.RuntimeHelpers.takeOuter@274[T,TResult](ConcatEnumerator`2 x, Unit 
unitVar0)
        at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
        at Microsoft.FSharp.Collections.SeqModule.ToArray[T](IEnumerable`1 source)
        at Paket.InstallProcess.InstallIntoProjects[a](InstallerOptions options, Boolean forceTouch, DependenciesFile 
dependenciesFile, LockFile lockFile, FSharpList`1 projectsAndReferences, FSharpMap`2 updatedGroups)
        at Paket.UpdateProcess.SmartInstall(DependenciesFile dependenciesFile, UpdateMode updateMode, UpdaterOptions 
options)
        at <StartupCode$Paket-Core>.$PublicAPI.Install@266.Invoke(Unit unitVar0)
        at Paket.Utils.RunInLockedAccessMode[a](String lockedFolder, FSharpFunc`2 action)
        at Paket.Program.handleCommand@822-11.Invoke(ParseResults`1 results)
        at Paket.Program.processWithValidationEx$cont@42[a](Boolean silent, FSharpFunc`2 commandF, a result, Unit 
unitVar)
        at Paket.Program.processWithValidation[T](Boolean silent, FSharpFunc`2 validateF, FSharpFunc`2 commandF, 
ParseResults`1 result)
        at Paket.Program.handleCommand(Boolean silent, Command command)
        at Paket.Program.main()