I do not know if this helps:
JamesH version (for XP 32 bit) http://www.gimpchat.com/viewtopic.php?f=8&t=2241&hilit=JamesH&start=40
also has requirements for ui:
Error loading UI file 'C:/msys/opt/GIMP-2.7/share/gimp-apng\ui/plug-ins/plug-in-
file-apng.ui': Failed to open file 'C:/msys/opt/GIMP-2.7/share/gimp-apng\ui/plug
-ins/plug-in-file-apng.ui': Permission denied
(file-apng:3840): Gtk-CRITICAL **: gtk_container_add: assertion `GTK_IS_WIDGET (
Although a strange location (ui) - it works - thank You for sharing.
I have been investigating and it seems a little more of an issue than I originally thought. The problem is that during compilation of file-apng.c, the datadir is passed in and the ui_file location gets sort of hardcoded into file-apng.exe. If you have access to strings and you examine file-apng.exe then you will see the above location in the executable file. I will continue to investigate whether I can make the exe location independent. This will take time since I have to figure out how the authors coded the whole shebang.
In the meantime, if anyone is interested to use apng, you will have to do what MareroQ did (for 32 bit). For 64-bit check the error and create the appropriate location.
BTW, the "strange" location is my development environment - separate for 32-bit and 64-bit.
Sorry for the "inelegant" solution for the time being.