Add a schema to the Record Set before attempting to add a record interactively.Setting the feature set and record set schema:In ModelBuilder, right-click the feature or record set variable and select Properties.Click the Data Type tab.In the Import schema and symbology from field, enter or browse to the path of the dataset to use as the schema source, and click OK.<a href="http://desktop.arcgis.com/en/desktop/latest/analyze/modelbuilder/setting-feature-set-and-record-set-schema.htm#ESRI_SECTION1_026B03D805104DCDB10BCFCCC5952B4E" target="_blank">http://desktop.arcgis.com/en/desktop/latest/analyze/modelbuilder/setting-feature-set-and-record-set-schema.htm#ESRI_SECTION1_026B03D805104DCDB10BCFCCC5952B4E</a>