Error: The LeanFT runtime engine could not be launched.

This error may happen while trying to open Visual Studio or Eclipse IDEs.
There are two possible causes identified:

1. When checking the LeanFT Client logs (HP.LeanFTClient VS or HP.LeanFTClient Eclipse), we find the following message:
   2016-08-31 14:25:21,445 HP.LFT.PackageManagers.License.LicenseService [   1] ERROR Connect: Failed to connect to LeanFT runtime engine on ws://localhost:5095/.
   HP.LFT.Communication.SocketClient.CommunicationException: Connect: Failed to connect to LeanFT runtime engine on ws://localhost:5095/.
      at HP.LFT.Communication.SocketClient.SocketConnection.Connect(Uri uri)
      at HP.LFT.Communication.SocketClient.ConnectionFactory.Connect(String address, ConnectionConfiguration config)
      at HP.LFT.SDK.Core.Communication.CommunicationClient.Init(ISdkConfiguration config)
      at HP.LFT.SDK.SDK.DefaultRunSeession.Init(SdkConfiguration sdkConfig)
      at HP.LFT.SDK.SDK.Init(SdkConfiguration sdkConfig)
      at HP.LFT.SdkUtilities.SdkInitializer.Init(Uri serverAddress)
      at HP.LFT.SdkUtilities.SdkInitializer.Init(Uri serverAddress, Boolean& hasValidLicense)
      at HP.LFT.PackageManagers.License.LicenseService.HasValidLicense(Uri serverAddress)
   By default, LeanFT Runtime Engine uses port 5095 as communications port. If this port is being used by another application, the mentioned error/warning message will show up.
2. A second possible cause would be that the "Prevent access to registry editing tools" security policy is enabled for the user that is trying to launch LeanFT Runtime engine. Such policy doesn't allow the use of system registry editing tools like regedit.exe or reg.exe. There are two ways to confirm whether this is the cause:
   1. Check whether the mentioned policy is enabled: Go to Start>Run, type gpedit.msc and press Enter key. Then navigate to User Configuration>Administrative Templates>System and check whether "Prevent access to registry editing tools" policy is enabled or not.
   2. Another option would be to run a .bat file that will try to query the registry like LeanFT does and check whether it is able to retrieve the data from registry. See sample .bat file script:
      @echo OFF
      FOR /F "usebackq tokens=3*" %%A IN (`REG QUERY "HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Mercury Interactive\LeanFT\CurrentVersion" /v LOCAL_MLROOT`) DO
      (
          set appdir=%%A %%B
      )
      ECHO %appdir%
      pause
      If it shows the following error message: "Registry editing has been disabled by your administrator", then LeanFT is having the same issue and hence the problem.