So today I installed a fresh copy of Tixati and started downloading a file that was approximately 1,8GB large, everything was going smoothly and without problems but then suddenly it showed Unable to open File: The process cannot access the file because it is being used by another process error, so I just clicked Stat button and it was downloading again. But after a few minutes it showed the error again. I run Tixati as admin and it is installed on an account with admin privileges.

send that torrent to the devs with explanation. support@tixati.com

i got the same error message sometimes, most likely my antivirus program locking it. When i disable the avast, the problem gone.

Yes had same problem. I removed avast and download went fine.