I am trying to slice a model in Cura 4.8 but the model shows stripy and when I try to slice I get the following message, Unable to slice, Please review settings and check if your model, : fits within the build plate, : are assigned to an enabled extruder, : are not all set as modifier meshes. The model does fit within the build plate, I have only one extruder so assume it is permantently enabled, I have not had trouble printing other models. I'm not sure I understand the last one but I am only trying to slice one model so assume there's nothing to set there. I did have this problem with another model and when I enable a brim the message went and the model turn to yellow, however this doesn't work with this particular model . Can anyone help please?