Recently, I had some difficulty to update High Sierra 10.13.4 beta 4 thru App Store update section. There has been no problem so far until 10.13.4 beta 3, it was very strange and I found I am not the only person has this problem. It must be a bug (because someone has no problem with that) from Apple’s side and I guess it will be fixed soon. However, since I really wanted to test Beta 4, I found a fixable method (It worked on my system at least and so far it looks good) and shared it here.