are you defining your streamlines at a no slip surface? If so, there shouldn't be streamlines on that surface.

First of all iit is warning not error which means that you could be able to produce any other results.

Second, you may defined the stream lines at a surface body. If you have defined Named Selection called surface_body then check where it is defined. It seems that it is a surface (where no slip boundary condition is defined as Rafael Said) remove it and everything will be fine.

Best regards

Mohamed

thank you Rafael and Mohamed

i can proceed with the results yes