1. If the SIS file needs to be optimized, Vision 4D will ask you to select the Defragmentation method.
   

1. Select one of the following methods:
   1. Fast Defragmentation = Performs a fast, but less efficient, task.
   2. Full Defragmentation = A complete optimization is applied. It takes more time. (Suggested)
2. Wait until the defragmentation is completed.