Create a Control-M Managed File Transfer job and Check In.
From the Control-M/Enterprise Manager Planning or Monitoring domain, view the job details by double clicking the job, and modify the File Name or Path for an MFT job and save the changes.
Reopen the job and the previous modifications were not saved and nothing changed in the job definition.
CTM-4135 has been created to track this issue and is resolved in Control-M Managed File Transfer 126.96.36.199.
Apply the latest available version to resolve this issue.
If you are unable to apply the latest version, use the edit mode option in the right pane of Planning or Monitoring and edit the job definition from here.