Hello there!
Please check the following:
1. check the CPU and memory usage while trying to run the third CE. If they are high, it is the specs issue (we tested from our side - 3 CEs impacte the CPU about 100%);
2. log in to the laptop BIOS settings and make sure the CPU virtualization or the related settings are turned on;
3. during the opening of the third CE, open VirtualBox and check if the third machine can boot up normally on VirtualBox like other machines. If not, please install the latest version on VirtualBox.
4. If the issue persists, please show us the error screenshot.
Thanks!