Win32: The procedure entry point deflateSetHeader could not be located in the dynamic link library libgio-2.0-0.dll

[benryves]

This isn't specifically an issue with TiLP, rather just the awkwardness of getting GTK+ working on Windows, but I think it may be something that's worth highlighting in the documentation.

If you use the version of the GTK+ runtimes linked to from http://lpg.ticalc.org/prj_tilp/win32.html this error doesn't appear and TiLP runs but the menus are missing so you can't interact with the software properly. If you use the version from https://sourceforge.net/projects/gtk-win/files/GTK%2B%20Runtime%20Environment/GTK%2B%202.24/ then you may run into this message (I certainly do):

Somewhat unintuitively the issue is not with the DLL mentioned in the dialog box, but is an issue with zlib1.dll and appears because some other zlib1.dll on the system is being loaded instead of the one that GTK+ is expecting. To figure out where this is, you can use Dependency Walker or a modern equivalent - when opening tilp.exe in DependenciesGui.exe you can see where the problematic zlib1.dll is being loaded from:

In my case I renamed this zlib1.dll to ~zlib1.dll and TiLP now runs as it should. If I find out which other piece of software was relying on that incompatible version of zlib1.dll then I can rename the file back which is why I'd recommend renaming rather than deleting.