impossible to use work plan. . .

[emi_973]

Good morning to all,
I have a problem with revit 2010, which gives me this error message when I give the floor command. It only happens to me in this view, while on p.t. and on the cover floor no.
Someone can tell me where I'm wrong.
I attach screenshots.
Thank you in advance.

 

[lance]

probably for some reason there is set up an unsuitable work plan.
tab start>Select floor by name> in drop-down menu choose the level on which you want to draw the floor.
Hi.

 

[emi_973]

I had set a wrong plan! I had to have messed up something... now I solved. Thanks for the help.