Assembly Meshing is using Fluent Meshing in background. After launching the meshing operation you will see a Fluent process appearing in your task manager. If there is no available Fluent-Meshing compatible license available, the meshing operation will fail with the following error message. “Error in Assembly meshing. Aborting meshing An error occurred while running the Assembly mesher. Please check the geometry or the mesh settings for problems The mesh generation was not successful.” Conclusion: You will need a Fluent Meshing license if you want to use the assembly meshing option in ANSYS Meshing.