The , selected from the is useful to check your installation, and find out if Kst thinks something has gone wrong. The Data Sources tab lists all of the data sources that Kst has successfully loaded. If you are using a data file that depends on a data source plugin that is not listed, then there is probably something wrong with your build or installation.
The Log tab provides a log the loading of all data sources and data plugins, as well as logging some errors, such as out of memory errors. This log tab can be a useful place to look if things are not working out well.