Redownload client and replace .dll file from "game" directory
I Try all time ,but my antyvirus ,delete all time your files.https://gyazo.com/b54fa56e8b0d9e2bc5685c48260e9f64
It's a false positive, we will mail them about that. Meanwhile I'd suggest to add Tibiantis client to exceptions in your AV.
Reported to Norton, they will remove false positive at next update of signatures