The 1955 Le Mans disaster was a major crash that occurred on 11 June 1955 during the 24 Hours of Le Mans motor race at Circuit de la Sarthe in Le Mans, Sarthe, France. Large pieces of debris flew into the crowd, killing 83 spectators and French driver Pierre Levegh, and injuring around 120 more.

Generally there are two main reasons this can happen. Either the mods are conflicting with each other, or not up to date with the latest version of the game. Best solution if it is one of these - figure out which mod(s) are causing problems. Start with one or two mods, check that they work.