5
ok.. In ftp check to see the exact name of the renamed folders (orig. xoops_data, xoops_lib) and then in mainfile make sure all mentionings of xoops_lib and xoops_data reflects the new names.
If this doesnt work, and both folders (xoops_data, xoops_lib) are present in ftp, then something else is wrong.
In that case I would upload "/install/" and blank mainfile.php again and run install from the beginning to see if you could catch up on something.
Programming is like sex:
One mistake and you have to support it for the rest of your life.