Blank after upgrade

I updated the website from Version 3.0.1

And did you follow the extended upgrade instructions?

https://codex.www.ads-software.com/Upgrading_WordPress_Extended#Upgrading_Across_Multiple_Versions

Do you have a full backup of your site and database from prior to updating?

No, I took a chance, and thankfully this is just a test-version of the real site.

Approximately, how long would this step-by-step upgrade take?

Depends on how fast you can move files and how fast the server is. Shouldn’t be excessively long – but given that you need to do about 5 iterations, a bit of time.

5 only?
I thought it would take more than 40 at most?? And if I can skip one or two, at least I will have to do 22?

Major upgrades mean the tenths – so 3.01 to 3.2 to 3.4 to 3.6 to 3.8 to 4.0 to 4.1.1 should be okay. I guess that’s 6.

Ah ok! But I’ll have to transfer the original files from my back-up first?

Yes, and hopefully you have a database backup to restore too?

Yes thanks for your help!

This is what I’ve done:

I uploaded the backup (.sql) in phpMyAdmin and everything went smooth. I changed the URL towards my test-site. I almost reached the admin login-page but directly I was re-directed to https://test.prema.se/wp-admin/upgrade.php.

So I clicked to upgrade – and now I’m back to square one again!

How come I was redirected to upgrade.php? Have I missed something?

This is where I get redirected to: https://test.prema.se/wp-admin/upgrade.php?_wp_http_referer=%2Fwp-admin%2F
And I only want to log in to my admin here: https://test.prema.se/wp-admin.

I checked all the files in public_html and changed the URL.