When you combine them, the most plausible explanation for this specific error is that you are trying to use a login/password combination that does not match the one the mod/custom game launcher is expecting. This is a very common problem with unofficial game releases. This specific error message is part of the official Rockstar Games experience. Instead, it likely comes from a third-party launcher or a modified game client designed to bypass the standard login servers.
The classic "Email or Password is Invalid" error can often be fixed by: When you combine them, the most plausible explanation
What or code does WinRAR or 7-Zip display? What is the total file size of the archive you downloaded? Instead, it likely comes from a third-party launcher
: Place part1.rar , part2.rar , etc., into the exact same folder on your hard drive. : Place part1