Fill colour not possible

[TwoBeAss]

Hi, i have a strange problem with some of my shapes.. Some of them dont change the background when a fill colour is applied... No one is locked or anything like that.. I could not spot the difference between the two shapes..
See attached file..

Thanks for your help,
Tobi

[Croc]

See layer

[Croc]

Drawing Explorer

[TwoBeAss]

Thanks for opening my eyes.. I checked nearly everything except for the layers!
Sometimes its more easy then expected...