Upgrade 3.8.9 to 5.1

[MRMRacing]

I'm trying to upgrade, has tried several times with same result. PhP is 5.4.1. I have deleted all files from the 3.x.x, uploaded the new files (deleted the install.php). Run the upgrade.php scrip, makeconfig.pgp starts and makes the changes to config. Then it deletes the makeconfig.php and re-directs to install.php ?? That should be deleted when upgrading according to the manual.

Should I keep the install.php when upgrading despite instructions says delete?

[MRMRacing]

OK, I understand the file should be deleted so it's not overwrites the old database. But after the makeconfig.php is deleted it redirects to the install.php (deleted). What should I do after that?? If I try to access the forum or upgrade.php again it redirects like this forum/core/install/core/install/core/install/core/install/core/install/core/ins.....what is wrong. Thanks!

[MRMRacing]

Found out that my config.pgp needed "fullt path to the forum" so after that the upgrade started. So now I'm hoping the upgrade will end successfully

[Wayne Luke]

You shouldn't be deleting the install folder until you are done with the upgrade. Deleting it prematurely will cause the errors you're seeing.

To upgrade to you have to

1) Delete your 3.X files.
2) Make a backup of your current database and download it to your local machine or store it on a cloud drive.
3) Update the /core/includes/config.php file to point to your current database.
4) run /core/install/upgrade.php. If you have a larger site with millions of posts, you'll want to do this from the command line. 'php /pathto/core/install/upgrade.php'

Go through all the steps.