Follow these steps in order. Do not skip the diagnostic checks.
Uninstalling old versions of Proteus (v7, v8) often leaves orphaned registry keys that confuse the v8 or v9 License Manager. Follow these steps in order
Follow these troubleshooting methods in order to resolve the licensing conflict and restore functionality to ISIS Professional. 1. Run Proteus as an Administrator Follow these steps in order
I can provide more targeted steps based on your specific setup. Share public link Follow these steps in order
If utilizing a physical USB key:
Here is a structured approach to tackle the error, ranging from the simplest fixes to a more comprehensive cleanup.
If none of the above work, a clean reinstallation might be necessary. Proteus through the Windows Control Panel.