Amanda Bynes Wasn't Invited To 'All That' Reunion

Amanda Bynes won't be part of Nickelodeon's "All That" reunion -- she wasn't even invited.

Sources close to Bynes tell us she found out about the reunion when a trailer was released online ... she never got a heads up from producers.

Bynes got her start on the '90s sketch comedy series, and went on to star in her own Nickelodeon show, "The Amanda Show," a few years later.

Amanda tells friends she would've declined the offer anyway, because her focus these days is fashion, not acting.

As we reported, the "All That" reunion won't feature new material. Instead it will be a lot of reminiscing with "All That" alums Kenan Thompson, Kel Mitchell, Danny Tamberelli, Lori Beth Denberg and Josh Server.

Maybe producers just asked Ashley by mistake ...