If you have stared at your terminal or job manager, watching a simulation that has been running for 12 hours stop dead with the message "Failed to obtain exclusive access to license feature" or "Error 99998 exclusive mode required," you know the pain.

This error effectively tells the solver that it cannot lock the necessary computational resources or license tokens to proceed. The term "exclusive" is the key: Moldflow is trying to tell you that it needs sole, uninterrupted access to a specific license feature (e.g., moldflow_insight or moldflow_advisor ), and that access is being blocked.

Last updated: October 2025. This guide applies to Autodesk Moldflow Insight 2023, 2024, and 2025. Autodesk Moldflow error 99998, error 99998 exclusive, Moldflow license error, FLEXlm error 99998, exclusive access denied Moldflow, Moldflow solver failed.