Hi Oliver,
you need to build boost or a subset of boost with b2/bjam MASM, the assembler tool, ist part of MS Windows Driver Kit as you can read in the docu http://www.boost.org/doc/libs/1_60_0/libs/context/doc/html/context/requireme...
Thanks for your response, but please read again the command line I stated in my first mail: ml64 /Fo path/to/obj/file.obj /c path/to/source/jump_x86_64_ms_pe_masm.asm Please note that this already *is* the 64bit MASM executable as stated in the documentation. And using MASM64 leads to the aforementioned errors. The error messages were as follows: ------ 1>------ Erstellen gestartet: Projekt: boost, Konfiguration: Debug x64 ------ 1> Microsoft (R) Macro Assembler (x64) Version 14.00.23506.0 1> Copyright (C) Microsoft Corporation. All rights reserved. 1> 1> Assembling: C:\Projekte\DeadPlanet\SourceExt\boost\context\asm\jump_x86_64_ms_pe_masm.asm 1> C:\Projekte\DeadPlanet\SourceExt\boost\context\asm\jump_x86_64_ms_pe_masm.asm(80)ied size 1>: error A2008 : syntax error : FRAME 1> C:\Projekte\DeadPlanet\SourceExt\boost\context\asm\jump_x86_64_ms_pe_masm.asm(81)ied size 1>CUSTOMBUILD : warning A4020: directive ignored outside a procedure 1> C:\Projekte\DeadPlanet\SourceExt\boost\context\asm\jump_x86_64_ms_pe_masm.asm(215 1>CUSTOMBUILD : fatal error A1010: unmatched block nesting : jump_fcontext ------ So again the questions: a) Is this the correct asm file for Visual Studio, x64 architecture? b) If yes, where do those error messages come from? It's the same source file, the same build tool, the correct invocation parameters, and no includes or configuration referenced from that ASM file - should result in the same object file, shouldn't it? For reference: the 32bit version builds and links fine. Command line for 32bit is: ml /Fo path/to/obj/file.obj /c path/to/source/jump_i386_ms_pe_masm.asm All: I will not use bjam, as stated before: it does not allow the necessary fine control over the compiler settings, e.g. the compiler choice v140 vs. v140_xp. Ignoring this will build just fine but leads to rare crashes which unfortunately do NOT happen on systems with debugging capabilities but only on some client systems with *days* of response time. This is not fun. So please, do not discuss the environment. Discuss the actual issue at hand instead. Thanks again. Bye, Thomas