Update the nothing to slice message

The message didn't list all the cases that it could pop up.

CURA-7277

plugins/CuraEngineBackend/CuraEngineBackend.py

@@ -421,7 +421,10 @@ class CuraEngineBackend(QObject, Backend):
 
         if job.getResult() == StartJobResult.NothingToSlice:
             if self._application.platformActivity:
-                self._error_message = Message(catalog.i18nc("@info:status", "Nothing to slice because none of the models fit the build volume or are assigned to a disabled extruder. Please scale or rotate models to fit, or enable an extruder."),
+                self._error_message = Message(catalog.i18nc("@info:status", "Please review settings and check if your models:"
+                                                                            "\n- Fit within the build volume"
+                                                                            "\n- Are assigned to an enabled extruder"
+                                                                            "\nr- Are not all set as modifier meshes"),
                                               title = catalog.i18nc("@info:title", "Unable to slice"))
                 self._error_message.show()
                 self.setState(BackendState.Error)