mask

[Дарья32743777q383]

When I copy the mask to another layer by holding down the Alt key and dragging, nothing happens, although the action is shown in the history panel. How to fix this problem?

[Ged_Traynor]

@Дарья32743777q383 what exact version of Photoshop are you using, it's working fine for me with Photoshop version 25.0, have you tried manually resetting your Photoshop preferences
https://helpx.adobe.com/ie/photoshop/using/preferences.html#Manually
Remember to backup your settings before doing the preference reset
https://helpx.adobe.com/ie/photoshop/using/preset-migration.html

[Trevor.Dennis]

Can you confirm that you are talking about a Layer Mask as below?

What happens if you just drag without any modifier keys?

Is the target layer locked?  That would prevent the layer mask moving to it.