When you create a new block, you should place it in the project's default blocks directory. This directory is found in the project's catalogs directory. The blocks directory has a name in the form project_name blocks. So, for example, the default block directory of a project named My_Project will be catalogs\My_Project blocks. If you place the block in the default block directory, scenarios created in the project will automatically find them and make them available in Event Modeler when you are displaying the scenario.