Does index.php exist in the root directory ?
Can You check with phinfo.php <?phpinfo();?>
: _SERVER["PHP_SELF"] is for example info.php _SERVER["SCRIPT_NAME"] is also info.php
Can You put the directory rights to 755 ? (filezilla - and try a new installation with filezilla)
Your error is quite seldom. It my be caused by directory-rights which are set by a security-shield of the provider or by errors in filetransfer, seldom by a missing parameter of the provider (I hope You do not have a vserver where You must do many things manually?)
If You use filezilla as ftp-client it is much easier. If You use sftp then the client can use UTF-8 instead of ascii.
1. You can klick in filezilla with the right mousekey at the installation-directoy and then klick at the bottom of the popupwindow (at ..rights) and then fill in 755 and also for the files and directories beyond(hooks).
2. The next thing is to open a new file in notepad++ portable and fill in <? phpinfo(); ?> and save it as phinfo.php - and then copy it into the installation directory.
3. If You put a domain or a subdoman(for test) on the installation-directory , the You can go in Your browser at domain.com/phinfo.php .
A long window will open and You will see entries for _SERVER["PHP_SELF"] and _SERVER["SCRIPT_NAME"] - which are hopefully not empty.
4. My proposal is to delete the old installation and to install the master from github/typesetter because it is the most progressed version.
Please use the reliable filezilla-portable for filetransfer, because i had already problems with other clienrts. If You are unsafe try this first.