Hi.

I think in your case there should not be difficulties with migration. And of course you must check all the extensions of which preupdate checker reports and delete or update them before migration.

Prepare your J3 site for migration, create a backup, for migration, use this backup with a new database. If you fail, do not restore the site with the same database. Return to the backup, check it again. Create backup again and use a new database.

I made many migrations from J3 to J4 with SP Page Builder and Helix Ultimate without any problems. Perhaps the reason for the error in your case is route66

Hi Alex,

It's me again, in general error 500 can be caused by many things, I guess we talk about front-end error.

In most cases what is wrong is stored in error_log file in root folder.

You can also switch template to different one, Joomla default - to check one by one, what causes that crash.

Check subpages, by links - to check if error is on all - or only selected pages. It's play for 30min at least,

SPPB and Helix should work on Joomla 4.1.x

Yes, you can also disable all extra components and plugins before joomla upgrade - and turn on - one by one, to check them deeply.

build the website from scratch on Joomla 4

Not from the scratch, becuase you can migrate content, template settings.

I would try method 2 first.

Thank you, guys)!