Can I bypass the 'incomplete measure' error temporarily for playback or editing?

No, you cannot bypass the 'incomplete measure' error in MuseScore. The error is a fundamental validation check that prevents the software from proceeding with potentially incorrect musical data. While you can work around it by adding notes or rests, the error will persist until the measure meets the time signature requirements. Ignoring the error will likely lead to playback problems or other inconsistencies later in the editing process.