Hi, I'm getting several instances of the following kind of error when I build my code, which does not use boost::thread, etc., as I use the STD versions: 1>c:\program files (x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.16.27023\include\condition_variable(1 24): error C2872: 'xtime': ambiguous symbol 1>c:\program files (x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.16.27023\include\thr\xtimec.h(18): note: could be 'xtime' 1>c:\program files\boost\boost\thread\lock_types.hpp(31): note: or 'boost::xtime' My research turned up: https://svn.boost.org/trac10/ticket/11477?cversion=0&cnum_hist=10 So I added the following value for Windows 10 to my preprocessor: _WIN32_WINNT=0x0601; Unfortunately, this makes no difference. Can anybody advise me of a way forward, please? Best wishes. Tim Burgess Raised Bar Ltd. E: mailto:tim@raisedbar.net tim@raisedbar.net M: +44 (0)7989 486976