EpicGamesLauncher installation file CAB corruption

I was unable to repro this issue on win10 but I am looking into it further. There is a new version of the installer that you could try but I suspect this issue is not installer related but has something to do with your unique setup. One thing that you could try is to install from a folder outside of your user directory.

While I check out the log in more detail you could do a a quick internet search for the error code you encountered. That error, Error 1335, is one of the well known Windows Installer error codes and there are a number of tips on how to one might get past the issue. Maybe one of those tips will be helpful in this case.