Hi Mahmoud,
Does this message appears when you open fresh session of workbench, or directly you are clicking on model file and trying to run it on workbench.
Check if you are able to launch standalone applications like mechanical, fluent, spaceclaim, discovery.
Also try to clear the cache and reset the configuration, goto start menu type %appdata% and rename Ansys folder to Ansys.old, %temp% and rename .ansys folder to .ansys.old, try to relaunch and run the simulation.Â
You are navigating away from the AIS Discovery experience