Faced t he same problem and I realised that this happens when you are trying to open a cfdst file that is already open!
Try closing all the SmCFD windows and restart the windows. Perhaps it may solve this.
Thanks. I didn't have any other instances open; maybe has something to do with the cloud. I did stop the job and then cancel the instance on the cloud. I had another job that ran fine and when I tried to open the file again after a few weeks I got this error. I really need to be able to open these jobs.
Yes I think I have. I think it happens when an instance is already open. Occasionally all icons and any evidence of the running program will vanish, but it will be running in the background. Maybe a problem with multiple monitors. Check task manger to see if it is running an instance that you did not know about.
Unfortunately I don't think this is the case. I have rebooted my PC a few times and no luck. I've run other simulations just fine, solving them and opening and closing them with no issues. I even tried copying the one that doesn't open to a thumb drive, then opening on a differnet computer, and no luck. It seems something perhaps got corrupted in the file. I can open the support file just fine also.