Classifications, Expression is evaluated but results doesn't show up in label

[DavitBotchorishvili]

Hello. I am trying to create expression to calculate (zone gross perimeters - door width). when i select zone and check evaluation in property manager it gives me proper result and everything seems all right, but when i create custom label and select the property it doesn't show the result. When I try to customize built in stamp I can't even find the property in the list. 
Notes: 
I made it available to ALL
the property is located in new group that is available to all classifications as well. I have tried to relocate new property to existing groups but results were the same. 

Operating system used: Windows 10

[Barry Kelly]

Are you sure the label is associated to the zone?

When you hold SHIFT and hover over the label as if to select it, the zone should highlight as well if associated.

Barry.

[DavitBotchorishvili]

Yes. I am sure. For the experiment i used zone in open space without any possible overlaps 

[Xandros]

This still doesnt rule out, that the label might not be associated to the zone.

A few thoughts in mind:

• While placing your label, check that this method is selected
  
• Another way to check if your label is associated to an element is via the label settings. If the highlighted option is not visible = not an associated label
• What ArchiCAD version are you using? I do believe that the possibility of labeling zones was introduced with version 25

Edit: I've checked now and this expression doesn't show up for me either. I remember reading somewhere that there are some expressions that don't show up in graphic overrides (and apparently labels as well) but can't find the post that mentions that. So can't give you right now the specifics to it...

[Xandros]

https://community.graphisoft.com/t5/Graphisoft-Technology-Preview/Expressions-Labels-and-Graphic-Ove...

here's the mentioned topic I was referring to