Hey there, Farrokh!
Good job with the successful data recovery!
However, "The Parameter is incorrect" error is rather concerning. I'd recommend to test the external using your HDD manufacturer's diagnostics tool. It will tell you what is the drive's health and SMART status.
Since you've already backed up the data from the drive somewhere else, you can give chkdsk a try as well. You just need to open the Command Prompt in Windows (Run as Administrator) and type this command in the CMD dialog box: chkdsk /F /R /X Z: (where Z is the drive letter assigned to your external HDD).
Hopefully this will fix the issue. If it doesn't and you find any bad sectors or failed attributes in the SMART status, you should check your...