Are the font's characters spread across both texture pages?
No, the fonts are all on the first page.
Purely out of curiosity, does the warning disappear if you assign the font to a separate texture group?
No.
Other info: this issue is happened when I added new chars to Range (spanish chars). I noticed if I using "Add Range from file" doesn't work. It's add chars only if I use "Add Range from code", but will be this issue.
The message happears also if I click on "Regenerate" button.
Update:
Now it works. I've delete all fonts and recreted. Then added the Range via file. Dunno why, but it fixed.
In general do you keep different fonts for each language (spanish, italian, etc..)? Or all in one?