Hi Xuan,
Thank you for your post.
There are generally two common reasons that cause this issue. Open the Services application and scroll down to “CostX Database”, “CostX Auth”, “CostX Core” and check the Status. If they are not running, right click and select “Start”. If you have done this and the services fail to start or are missing, then this may be due to a firewall or antivirus software assuming that iTWO costX® is malware. In this case, you will need to either add the RIB program folder to the AV exclusions list, disable the AV scan and run iTWO costX installer again to repair iTWO costX services.
Also, kindly inform you that please you could refer to our Student FAQ as it will help to answer most of your questions. https://education.itwocostx.com/support/forum/student-faq/
Hope this helps!
Regards,
iTWO costX Forum Admin