Well I can't import them myself, APNG don't show because they're not a "SPI compatible format".
On the file selector, manually enter *.apng
the file appears, click on it. That's how I did it,
and it worked. Beware doing this though, it will only read the first frame from the APNG, as it's stored as a normal PNG stream and probably ignore the rest or error. LGM does not import directly from APNG.
If that was a non animated sprite, you could rename the APNG to PNG. Any PNG reader will be able to read the first frame of the PNG.
I only did this for testing purposes.
Another fact here: I haven't even set my ENIGMA installation to Spanish. But somehow it has always been like that, in spanish by itself.
This is absolutely strange even paranormal
Is your windows version spanish ? Maybe somehow it is detecting some keyboard/language settings and saving info into the EGM ?
As strang as it may sound, maybe this has to do ? Some glitch/bug in LGM ?