Cannot convert to WebP

[zecanard]

Hello,

NConvert for macOS fails to convert this XKCD comic from PNG to WebP:

~/Desktop>/opt/NConvert/nconvert -out webp exploits_of_a_mom_2x.png

** NCONVERT v7.300 (c) 1991-2026 Pierre-E Gougelet (Aug 4 2026/12:24:03) **
** This is freeware software (for non-commercial use)

Error: This picture cannot be written using this format (exploits_of_a_mom_2x.webp)

I’m able to convert the image to WebP using XnView MP using both Save As and Batch Convert.

I tried with both v7.232 and the just-released v7.300. Both can convert to JPEG(li) just fine. Thank you!

[zecanard]

Just found 8-bit images need to be converted to True Color or 32-bit. Maybe this could be done automatically?