I do not if this one was bad, but surely ugly:

Out of WW2, there were surely many flops. "Bad" meaning either endless design flaws or teething problems, or simply bad performance in the cirkumstances faced.
Names like Fairey Battle, Douglas Devastator, even He-177, Me 210, SBC, oh, - it is a contest of many more.
As for wing bracing, I wonder why they didn't just strut the upper one. After all, lower wing aircraft are rarely strutted (upwards), although I belive I have seen a picture of one.
And as for wood and canvas.....I like it.