A "bad" mesh is the leading technical cause of Error 99998. If the solver encounters an element with zero volume or extreme distortion, the mathematical matrix becomes unsolvable.
Check Task Manager. If memory usage hits 90%+, the solver may trigger a 99998 crash. autodesk moldflow error 99998 best
Ensure the autodesk-moldflow-insight-license-configuration package is installed and matches your solver version. A "bad" mesh is the leading technical cause of Error 99998