[Measuring Tool and Assign Drawing Scale]

https://forum.affinity.serif.com/index.php?/topic/170644-measurement-tool-app-freezes-when-applying-a-scale/&do=findComment&comment=987661

 

[Measurement Tool: App freezes when applying a scale]

Make sure your document units (Document Setup) are the same as the drawing scale you want to assign. So set your document units to meters if you want to assign a drawing scale in meters.