It does not seem to make any difference what file, I was using the grep-changelog file in the bin folder for testing, but any text or source file seems to cause the problem. I was visiting the file by dragging and dropping it into the emacs window. Visiting a file using the menu or 'C-x C-f' does not cause the problem. Starting emacs with emacs -Q crashes if a file is visited. I have attached a traceback from the zlib-available-p function. I couldn't paste it here because it contains null characters (^@). Regards Bill Farmer On 26/11/2014 15:55, Eli Zaretskii wrote: >> Date: Wed, 26 Nov 2014 11:34:52 +0000 >> From: Bill Farmer >> CC: dmoncayo@gmail.com, 19181@debbugs.gnu.org >> >> I have downloaded a built version of zlib1.dll from the zlib web site >> (http://zlib.net) and copied the file into the bin folder of the emacs 24.4 >> distribution. This fixes the problem, as this version of zlib does not have a >> dependency on libgcc_s_dw2-1.dll. > Great, so your problem is solved. I've now mentioned zlib1.dll in > etc/PROBLEMS as the potential source of such crashes. > > However, I'd still like to understand why Emacs loads zlib1.dll when > you visit a file. Could you please help me figure that out? > > First, does that happen with any file, or just with a few particular > ones, and if the latter, then which files trigger that? > > Second, how do you visit that file, exactly? "C-x C-f", via the menu > bar, something else? > > And finally, does Emacs load zlib1.dll if you invoke it as "emacs -Q"? > If "emacs -Q" doesn't load zlib1.dll, can you try finding the > customization in your ~/.emacs that causes this? > > There are only 2 functions in core Emacs that might load zlib: > zlib-available-p and zlib-decompress-region. So another way of > finding out why zlib is being loaded is to "M-x debug-on-entry" both > these functions, and when Emacs pops up the Lisp backtrace, see who > called them. > > Thanks.