Idk why this sign is appearing

[Guigz.p (Guillaume)]

Hi everybody !

I’m kind of a newbie on this app. It’s been 2 days since I started designing this typeface but suddenly there is this pixelated square that shows when i’m designing glyphs. You can see it on the screenshot.
I don’t know what that means and how to make it go… if somebody knows…

Thank you in advance for your help, have a great day

[GeorgSeifert]

You had added an image to that glyph. But that file can’t be found (maybe you deleted it or moved the .glyphs file). You can click the icon and delete it. If it can’t be selected, right click it and do “Unlock Image”.

[Guigz.p (Guillaume)]

thank you very much !