According to a representative for Six Flags, the Jokers Jinx had an issue with one of the train’s wheel. It has since been fixed.
In a statement (via Fox 45), Six Flags said, “I wanted to respond to all who asked for an update about JOKER’S Jinx. Please know the safety of our guests is always our top priority. After a thorough inspection of the JOKER’S Jinx roller coaster, Six Flags corporate engineers and certified ride technicians identified an issue with one of the train’s wheels and took comprehensive action to resolve it. State of Maryland ride inspectors cleared the ride to be put back into service. Six Flags America has reopened JOKER’S Jinx and we are open daily through Spring Break April 23.