This page describes the concept of the Analysis mode. Basically, the software switches to Analysis mode after the simulation has finished running. Typically, analysis mode allows you to view simulation results but not make change to the simulation setup. To change the setup, switch back to Setup mode.
In Analysis mode, simulation object properties can be viewed ( 
symbol means the object has data or results, similar to havedata and haveresult command) , but not edited. This ensures that at any given time, the simulation data results corresponds to the configuration of the simulation project. Once in the analysis tool, the user continues to analyze the simulation data until they either wish to close the application, or they decide to alter the simulation objects and re-perform the simulation. By exiting the analysis routines and returning to the layout editor, existing simulation data will be erased.
If you would like to keep the existing data and re-run a simulation, the easiest way is to save the simulation with a new file name. Then the new data will be saved to the new file. Another way is to send the data to your Script Workspace, data in this field will not be replaced by re-running the simulation. To do this, right-click the results/data in the Results View , and choose "Send to script".
Simulation files in analysis mode (with simulation results) are typically very large. Switching them back to layout mode makes the file much smaller and easier to share.