This error may occur when launching iModel from iCommand if you have multiple instances of the software running at the same time.
You can either check your taskbar to see if the software is open multiple times:
Or use Task Manager to view open processes:
You will need to end task on all instances of the software that are running and then re-launch the software one time.
Please reach out if any further assistance is required.
Helpdesk: 866.237.2878
Email Support: helpdesk@alpineitw.com