Online and Desktop synchronization

When shifting from Online to Desktop, Simul8 sometimes gives an error message that the license use is duplicated.

This normally appears when trying to log in to your Simul8 online account while Simul8 is still open on Desktop or vice versa.

If you see this message, without using Online and Desktop simultaneously, follow these steps to resolve it:

  1. Open File Explorer
  2. In the search bar type: %programdata%
  3. Access the Simul8 folder
  4. Access folder that matches installation directory for Simul8, e.g. /CPROGRAMFILESX86Simul8
  5. Check if the dla.txt file is present

if so this indicates that Simul8 Desktop did not close correctly last time, carry on with the below :

  1. Open Simul8 Desktop
  2. Let it fully load (i.e. give it a minute)
  3. Close Desktop version
  4. dla.txt should disappear

If this persists and you are unable to find a dla.txt file in your installation directory, please contact If you can find a uulg.txt or a uulglog.txt in the same location, please attach it to the email you will send to the Simul8 Support Team.