Changing the measure number position will be effective not before mscore has been restarted
If I change the position of the measure number (Format->Textstilvorgaben bearbeiten->Taktnummer), the new position will not be effective before mscore has been restarted. So experimenting with trial and error for repositioning of the mesure number is rather painful.
My environment: Linux, Fedora 20, mscore-1.3-2.fc20.x86_64, German language
Comments
Just reload the score (Datei->Neu laden).
The next version will have this fixed, you could try a nightly build to check yourself
As another workaround for now, rather than needing to reload the score, just insert a line break somewhere or insert a measure or otherwise do something that forces new measure numbers to be generated.