Our group has been using DTI Tortoise for a final to process our DTI data. We are currently using version 2.5.2b. We have been running this successfully on a Fedora v26 server. We are in the process of moving to a CentOS 7 server and are trying to use Tortoise on this server. The prepvm step runs with no errors but have a problem when running calcvm on this. This has happened on several subject's data. We then ran these same subject's data on our Fedora server and had no problem with the calcvm step.
On the CentOS server, we start up calcvm and do the "load listfile" step. No problems. We do a QA on the images and find no problems displaying and checking these. When we click on the "estimate signal SD" button, the error below occurs:

There seems to be a problem about Spawn and managing a child process. I do not know what is causing this. Can anyone help understand what is causing this?
Thank you,
Mike Kerich