Solo: A Star Wars Story has the dubious distinction of being the fist Star Wars movie to not take over the box office and become a global smash hit. To be sure, the movie did just fine at the box office, but expectations for Star Wars movies are high, and Solo largely failed to meet them. There are a lot of reasons that this may have happened, but screenwriter Lawrence Kasdan seems to have decided that any faults in the movie could be traced back to "the studio."
In a recent appearance at the Austin Film Festival (via SyFy), the writer of Star Wars: The Empire Strikes Back appeared to claim that his final entry in the galaxy, far, far away faltered because of problems at the studio level. After helping out with the script to Star Wars: The Force Awakens, Kasdan apparently only agreed to write Solo: A Star Wars Story if he could do it with his son Jonathan. It seems the father and son writers had no issues with the film, but Lawrence Kasdan said that after the script left their hands, problems ensued. In his words...
Then the studio blew it. But that's not unusual.
Lawrence Kasdan doesn't elaborate on his statement, so we don't have any details on exactly what the accomplished writer is referring to. Having said that, it's not like we don't know a lot. The behind-the-scenes situation for Solo: A Star Wars Story is better known than most blockbuster movies, all due to the fact that Lucasfilm took the unusual step of parting ways with the film's original directors midway through filming.
Originally, the team of Phil Lord and Christopher Miller were hired to direct Solo, but they were replaced midstream by Ron Howard. It was reported that filming was taking an awfully long time with Lord and Miller, and that they were allowing for a lot of improv on set. This allegedly led to clashes with Lawrence Kasdan, and it seems ultimately the decision at the studio level was to side with Kasdan.
Since Lawrence Kasdan is seemingly now leaving Solo's situation at the feet of the studio, assuming the rumors of his clashes with Lord and Miller are true, it could be that Kasdan just thinks it was a bad move to bring them in in the first place. It could be that, it could be other decisions the studio made, which Lawrence Kasdan doesn't agree with.
Solo: A Star Wars Story wasn't a massive box office bomb. The film made just short of $400 million at the global box office in 2018. The issue is that, because of the additional costs associated with the director swap, such as a significantly longer than planned shooting schedule which led to a shorter than planned post-production schedule, Solo was a more expensive than planned movie, meaning it was going to need to make a lot to be profitable. That didn't happen. Solo is actually the lowest grossing live-action Star Wars movie to date.
Solo's lack of success is largely being held responsible for Disney's decision to slow down the release of Star Wars films. Original plans that expected us to see at least one movie a year have been shifted, and following the release of Star Wars: The Rise of Skywalker, the franchise will take a couple years off, before resuming with an every other schedule.