WinRAR 5.70 patch has not updated WinRAR 5.70.2 (beta 2) to version 5.70.0 (release).
That minor error happens often when a program comes out of beta not only in patchmypc i simply ignore it and install it myself and set the progam to skip this release.
WinRAR is a great software, I think that it is not neccesary patch, alway It works well
Only wait the oficial version I never used to beta version