I am running recon-all on Freesurfer version 6. Few of my subject's have XL  defect error as shown below.

CORRECTING DEFECT 0 (vertices=18408, convex hull=3300, v0=0)
XL defect detected...

This has been running for more than a day. 

How can I fix this error?
 Please give me some commands to solve this issue.

Looking forward to hearing from you