id summary reporter owner description type status milestone component version severity resolution keywords cc 12539 error category thread safety (system + asio) c++98 richard@… Beman Dawes " Foo.exe!boost::system::error_code::category() Line 355 I produced this with a global io_service and calling poll_once in a loop inside a second win32 thread. The program runs for an indeterminate amount of time before one of the calls to the handler results in an access violation (see above). Is asio meant to work without c++11 suppport?" Bugs new To Be Determined system Boost 1.60.0 Problem asio error category