ESBO tries to find a cooling load peak by running several months to find the worst one. In the current version of ESBO Light (2.0.3 and earlier), detailed results are only shown when all systems peak during the same month. If, e.g., the zone cooling load and the AHU cooling load peak during different months, nothing is shown. In full ESBO, the user is then allowed to select results from each peak month and view them.
A trick to limit the simulation to only a single month is to open the Location object, press User-defined design days, and then press OK. This will limit the available climate data (and simulation) to a single month (the hottest) and detailed results can then always be seen (for this month).