Cause

You are using a cross-section / diameter that does not conform to the project settings. In the Settings: Cross-sections / Diameters dialog (Options > Settings > Projects > "Project name" > Connections > Cross-sections / diameters menu option), you can set cross-sections or diameters that can be assigned to all connections in the project.

The value you selected is not listed in the table of settings.

Solution

Possibility 1

Select a value contained in the Cross-sections / diameters table. To do this, open the Properties <...> dialog for the connection or connection definition point concerned. Click [...] beside the Cross-section / diameter field. Select one of the predefined values from the Cross-sections / diameters dialog that opens and click [OK].

Possibility 2

Add the value that you want to use project-wide to the Cross-sections / diameters table of settings.

Select the Options > Settings > Projects > "Project name" > Connections > Cross-sections / diameters menu option. In the Settings: Cross-sections / diameters dialog, click (New) and enter the required value in the new table row. Then click [OK].

 

Refresh the connections and then start a new check run.