As seen in the pic, the files are ~/.config/opera/oauc_pipe and ~/.config/opera/oauc_pipe_r, and, as it is also desctribed in the error, they are "socket" filetype.
With a simple search, I found that socket files can not be copied or moved or tared, so you just ignore the errors and make the backup utility ignore them too.
thank you for the only good response out of all of them. i just found it odd, cause i've never seen any files in the user folder of any browser not backup before. thanks again.