Which OS are you using? Are you able to run the Questa software standalone?
Try below troubleshooting steps.
1. Run Quartus as administrator.
2. Try disabling any antivirus or firewall software temporarily, as they may be interfering with Quartus.
3. Install currprocess https://www.nirsoft.net/utils/cprocess.html and disable all the software running behind there
4. Try restarting Quartus and your computer. This can help clear any temporary issues that may be causing the error.
5. Check your system resources, including memory, CPU usage, and disk space. Make sure you have enough available resources to run Quartus.
Regards,
Richard Tan