Hi sangpan,
- Please list your Mac’s specs found here Apple menu >About This Mac>More Info> Add the information from this window (serial # not necessary)
- Have previous versions of the engine worked? If so, what is the last working version of the editor you had installed?
- Have you tried verifying the install: Go to UE4 Launcher (skip and let us know if you are using the Source Build)>Library>UE4.14Preview tab> Yellow Down Arror> Verify
- If this does not fix, try removing and reinstalling
Respond with the requested information if these steps do not resolve the issue.
Thanks,
.