The Flash still needs a director, but Warner Bros. is taking time to get the script right first.
Variety is reporting that Joby Harold has been hired to do a page-one rewrite of the script. According to Wikipedia, a page-one rewrite means that the script’s central premise or characters are good but the script is otherwise unusable, so Harold will do an entirely new draft.
Variety says that Warner Bros. didn’t like the direction that former director/writer Rick Famuyiwa took the script in, which is why they hired Harold for the rewrite.
The Flash was scheduled for a March 2018 release date, but is now pushed back to a later date. Warner Bros. will release their Tomb Raider reboot in March 2018 instead.