When you click Browse to select a timetable trigger in a simulation snapshot, a blank window opens although there many timetables defined in the project.
When you right-click the process and select Simulate, a window opens for you to select optional elements, such as timetables. From here, you select those elements if you plan to use them to configure your simulation.
If there is a timetable where the repetition period is specified to be years, but Day of week is selected under Selected interval details
a blank window opens.
Resolving the problem
Change the interval details by selecting Start time instead of Day of week. Then the Browse capability works when you set up a timetable trigger in a simulation snapshot.