EditGlyphData.app won't open .xml files containing same data as "GlyphData.xml"

I copied the contents of /Applications/Glyphs.app/Contents/Frameworks/GlyphsCore.framework/Versions/A/Resources/GlyphData.xml into a new .xml file, and placed this into a folder named Info next to my glyphs file (as per https://glyphsapp.com/tools/editglyphdata).

I am unable to open this file in EditGlyphData.app. There’s no error/crash, just nothing happens. I also tried opening GlyphData.xml, and this didn’t work either. I created a new EditGlyphData.app file (even created an intital unicode entry, so the file wasn’t blank, in case that helped), and selected Merge, navigated to both GlyphData.xml and my custom .xml file, and these didn’t work.

Any thoughts?

EditGlyphData.app, Version 1.0 (2)
MacOS Mojave, Version 10.14 (18A391)

Thanks!

I have just uploaded a new version of EditGlyphData. That might solve this problem.