Warner Bros. and DC Entertainment’s “The Flash” movie has hit another big speed bump: sources tell Variety that director Rick Famuyiwa has left the project.

Sources close to both Famuyiwa and the studio say creative differences forced the split. Similar issues arose with Warner’s “Wonder Woman” project after Michelle MacLaren left and was quickly replaced by Patty Jenkins without causing any issues to the production schedule.

Famuyiwa is the second director to exit the project, following Seth Grahame-Smith’s departure earlier this year. The studio is still expected to have another director in line shortly.

Warner Bros. had no comment on the news.

“When I was approached by Warner Bros and DC about the possibility of directing The Flash, I was excited about the opportunity to enter this amazing world of characters that I loved growing up, and still do to this day. I was also excited to work with Ezra Miller, who is a phenomenal young actor,” Famuyiwa said in a statement. “I pitched a version of the film in line with my voice, humor, and heart. While it’s disappointing that we couldn’t come together creatively on the project, I remain grateful for the opportunity. I will continue to look for opportunities to tell stories that speak to a fresh generational, topical, and multicultural point of view. I wish Warner Brothers, DC, Jon Berg, Geoff Johns, and Ezra Miller all the best as they continue their journey into the speed force.”

The move comes as a shock, given that pre-production for the film is already in high gear, and production was set to start in early 2017. The project was also far along in casting, most recently adding Kiersey Clemons to play Iris West and Billy Crudup to play Barry Allen’s father.

The movie was scheduled to be released on March 16, 2018. It’s currently unknown if this latest detour will force start of production and the release date to be moved.

After Grahame-Smith’s departure as director, the studio acted swiftly to replace him without any hiccups. This situation, however, is different; pre-production was in the very early stages at the time of Grahame-Smith’s exit, allowing the studio to regroup and focus on finding a new director. With pre-production so far along, change course now will be a tough hurdle to overcome, while still meeting deadlines.