Autodesk Moldflow: Error 99998

While rare, a material file (.udb or proprietary .materials) can have a corrupted rheological or PVT data set. When the solver calls the Cross-WLFL viscosity model parameters, it might receive a NaN (Not a Number) or infinite value. The solver cannot compute pressure drop and crashes.

Error 99998 is not a bug—it’s a signal. It tells you that your simulated molding process is physically unstable. Instead of forcing the solver, treat it like a real molding problem:

When you solve Error 99998, you don’t just get a simulation to run—you prevent a real-world short shot or burn mark. autodesk moldflow error 99998

Sometimes the GUI-based job manager fails, but the standalone solver works.

Moldflow requires 5–10x the size of your study file in free space on the %TEMP% drive. If your C: drive is nearly full, the solver cannot expand result arrays, leading to a write failure mapped to error 99998. While rare, a material file (

Before attempting fixes, you must identify the source. Based on analysis from Autodesk forums and support tickets, these are the most common triggers:

Moldflow’s solver communication timeout can be too short for large studies. When you solve Error 99998, you don’t just

If Moldflow crashes while saving, it may leave behind a hidden .lock or .lck file. When you reopen the study, the system believes the file is still in use by another process.

For any plastics engineer or mold designer, Autodesk Moldflow Insight (AMI) is an indispensable tool. It allows for the virtual validation of injection molding processes, predicting fill patterns, weld lines, air traps, and warpage before a single piece of steel is cut. However, like any sophisticated CAE software, it is prone to abrupt terminations. Among the most dreaded and cryptic notifications is Autodesk Moldflow Error 99998.

Unlike a standard meshing or solver error (e.g., Error 10002 for material data issues or Error 2000 for flow front instability), Error 99998 is infamously generic. The software typically outputs a message akin to: "Analysis failed. Error 99998 – Unknown error." This lack of specificity often leaves users feeling stranded, suspecting everything from corrupted geometry to a failing hard drive.

This article dissects Error 99998 from every angle. We will explore its root causes—ranging from file path conventions to Windows Registry conflicts—and provide a step-by-step diagnostic roadmap to resolve it permanently.