We are currently running IC 4.7.0 and PHP 7.4. We've been trying to update to PHP 8.0 and the latest IC version for a while, but we always run into the same problem. As soon as we enable PHP 8.0 with our hosting provider, the forum and more crucially the Admin CP are no longer visible, so we can't update the forum software.

How do we solve this "chicken & egg" conundrum?

Switch to PHP 8, upload the files manually then upgrade via URL: yourdomain.com/admin/upgrade

 

Switch to PHP 8, upload the files manually then upgrade via URL: yourdomain.com/admin/upgrade

Thanks. Where exactly do we need to upload the files to?

 

See Manual Upgrade.

That seems to be the solution, yes.

Thanks for the help, will post later to report success (hopefully)!

Unfortunately, it didn't work. We downloaded the latest version of IC, unzipped the files, uploaded the files to the server, overwriting where the same files already existed. Once that was finished for all files, we went to yourdomain.com/admin/upgrade. But that page does not open. Instead we get a 500 error (same with any other page we try to open such as yourdomain.com itself).

What did we do wrong?

 

What did we do wrong?

Have you run the current version of the ips4.php file on your installation, post-switching to PHP 8.x, and confirmed that all is good?

 

Have you run the current version of the ips4.php file on your installation, post-switching to PHP 8.x, and confirmed that all is good?

This helped!

It turns out we did not have the MySQLi PHP extension loaded. Now the update is complete, everything is running.

Thanks for the help @Nathan Explosion and @Adriano Faria!