To resolve an issue with the rolling cache size in Microsoft Flight Simulator 24 (MSFS24), follow these steps. First, navigate to your MSFS24 root directory, which is typically located at F:\SteamLibrary\steamapps\common\Limitless.
Inside the Rolling Cache folder, find and delete the single file that matches the set rolling cache size. This file should be of similar size as the specified capacity.
Upon restarting the sim, you will notice that MSFS24 has created a new rolling cache with its default setting at 16GB capacity.
Source: https://forums.flightsimulator.com/t/i-made-my-rolling-cache-too-big-and-now-msfs-wont-let-me-make-it-smaller/679033