I can't say that I recall encountering this problem. The list should consist of all the columns of the table being used as the fact table. You can see those columns in the source pane, which you can see by clicking on the show metadata checkbox in the view menu.
You will notice that there is an error overlay icon on the measure dimension (it gets propagated up to the cube and to the model namespace as well). Click on the measure and view the issues tab. Tell us what errors say. That could help us understand what cube designer thinks is a problem.
If you click on one of the issues you will be able to move the mouse pointer to select all the text and copy it.
How is this fact table (Segments) modelled in FM? Are there more than one table in it? What other characteristics of it are there? Is the schema defined by any macros? Macros in the metadata are not resolved, unlike during the running of queries. (see 16.3.5 Model cleanup and refinement in the dynamic cubes redbook IBM Cognos Dynamic Cubes | IBM Redbooks)Can you see factLedgerAccounts_Statistics in the package and the sources (when you import the FM package the schemas used in the package are brought into the sources pane as well)? In this picture you can see them at the top left.