User-defined attribute default value handling changed in 2018

Environment

Not environment-specific

Previously Tekla Structures used zero as a default value for user-defined attributes that had not been defined in templates and reports. Since 2018 Tekla Structrues does not set the default value and uses an undefined value.

This affects:

default values of all user-defined attribute types: text, numeric and option lists
both reports and templates in drawings

There can be some changed behaviour of templates that show UDA default values or use them in conditions. Previously you could for example use condition if GetValue("USERDEFINED.MY_UDA")==0 or GetValue("USERDEFINED.MY_UDA")=="" but now you need to use if IsSet("USERDEFINED.MY_UDA") to get the same result. This seems to affect at least some Russian templates which show wrong values or do not show anything, so for Russian customers we do not recommend to updgrade to 2018 version. The issue is being further investigated at the moment.