I have cygwin64 installed and up until recently, everything was working fine. However, I updated a while back and now I notice that emacs doesn't run: $ which emacs /usr/bin/emacs $ emacs $ emacs --version GNU Emacs 25.1.1 Copyright (C) 2016 Free Software Foundation, Inc. GNU Emacs comes with ABSOLUTELY NO WARRANTY. You may redistribute copies of GNU Emacs under the terms of the GNU General Public License. For more information about these matters, see the file named COPYING. $ emacs a.txt It doesn't really crash, it just returns immediately. So I thought I'd see what strace reported... $ strace /usr/bin/emacs 0 [main] strace 5196 D:\cygwin64\bin\strace.exe: *** fatal error - Internal error: TP_NUM_W_BUFS too small: 50. 614 [main] strace 5196 cygwin_exception::open_stackdumpfile: Dumping stack trace to strace.exe.stackdump Given that strace seems to be having problems, I'm assuming that the problem is more fundamental than just emacs (tho that's the only program I've found so far that has a problem). I should also note that while emacs claims v25.1.1, I just downloaded that today in hopes of a new install magically fixing the problem. The problem also existed with the previous v24.x version of emacs. See also attached (redacted) cygcheck.out Any ideas/recommendations?