Chris Quan
Ansys Employee

You may close all Workbench & Autodyn projects first, then browse to your ANSYS user directory at "C:\Users\user_name\AppData\Roaming\Ansys", and finally rename the folders "v222" and "v231" to "vxxx_old" or other names. You can re-create these folders by starting Workbench and then Autodyn again. This may fix the problem with Autodyn log file.

If the problem persists, you can open Autodyn GUI, click on Output -> Log File, and then check the button "No" to disable the log file. See attached picture below. Then Autodyn will not write the log file when it's running.