Hi Debtro, I just came across the same issue – this is how I fixed it.
This may not work on your host but worth a try.
Make sure the permissions on the two files are set at 644 (777 permissions on the files can cause your host to stop it working as these give too much access) – server 500 error.
Remove all extracted files from the previous install – start fresh, just in case you have done anything else.
Make sure you have not inadvertently deleted the .htaccess or any other files/directories such as cgi-bin (causes error).
Now when running the https://www.domain.com/installer.php do the exact same as you have… you will get the error but the files have extracted.
Go back to the installer and enter the details again (make sure Table removal is selected) but this time:
Go to “Advanced Options”
select: Manual package extraction
It will now work… or did for me on two separate domains i tested to be sure.
Good luck.
Stuart
