Advanced Sessions Generate Issue on 4.15 Release

Discovering modules, targets and source code for project…
Messages while compiling C:\Users\AdvSession\Intermediate\Build\BuildRules\AdvSessionTestModuleRules.dll:
c:\UsersUsers\AdvSession\Source\AdvSessionTestServer.Target.cs(29,48) : error CS0117:

‘UnrealBuildTool.UnrealBuildTool’ does not contain a definition for** ‘GetAllServerPlatforms’**

UnrealBuildTool Exception: ERROR: UnrealBuildTool encountered an error while compiling source files

Is this a problem with the build or the update? Has anyone come across this, or does anyone have any suggestions.

cheers,

-jr

There seem to be an answer in this thread