After installing macOS High Sierra, you should revert CoreStorage on your hard drive and doing so is as simple as running a command in the Terminal.
diskutil cs revert /
When done, save your files and restart the system.
The following two tabs change content below.
About The Author: Stephan Pringle is an Information Technology Specialist. He covers hardware and software and provides tips for you to troubleshoot and repair issues on your own. In his spare time, he writes articles about the State of New York on his Hackintosh and HackBook and that has helped him to become the top contributor of the New York City section of Yahoo! Answers.