Can't log request and response from mitmweb

Hi,

My machine is Windows 8.1 64bit, only mitmweb and mitmdump is active on my machine, the respective request and response are getting display in mitmweb portal but when i tried to generate logs of the same request and response in an external file, the files are getting generate but its EMPTY. Nothing is there in respective file, however expected is that file should contain all the request and response logs of mitmweb.

I tried -w outfile command to get flow of mitmweb into an external file, but the generated outfile is empty

i also tried to genrate a har file using the har file script but har file also not getting generate

Please help me to get these request and response log in an external file

Thanks

Regards,
Kapil