Version compatibility issues moving to October Rain 3.5.6

I am having trouble moving from October Rain v1.1 to the latest version.

Just a bit of a short background, I am moving from PHP v7.4 to v8.1 which also necessitates the move to Laravel 9. I have attempted various versions and cannot find a version of October Rain that installs via composer without errors, mainly related to removed classes. As an example I tried using the following:

"require": {
    "php": "8.1.*",
    "laravel/framework": "v10.33.0",
    "october/rain": "v3.5.6",
    "october/system": "^1.1",
    "october/backend": "^1.1",
    "october/cms": "^1.1",
    "ext-json": "*",
    "diff-tech/dt-php-base": "dev-main",
    "swaggest/json-schema": "^0.12"
},

Which results in the error: “Class “October\Rain\Foundation\Providers\ConsoleSupportServiceProvider” not found”

Removing all the missing classes from providers.php then leads to lots of other issues related to missing return types, scope of functions changing from protected to public, datatype inconsistencies such as Exceptions becoming Throwable etc. and all these are in October CMS code which I know I should not have to change.

I have tried multiple combinations of Laravel framework & CMS down to Laravel 9.0.0 & CMS version 3.0.0.

Can you assist us by letting me know exactly which version of Laravel is compatible out of the box with October CMS 3.5.6 or if there is something I am missing with regards to our composer.json or other.

The recommendation is to create a new OctoberCMS installation with composer create-project october/october and then move your theme and custom plugins to the new site. It’s much easier than upgrading.

If you adamant on upgrading, check that you have the correct versions for all dependencies. You’re using the incorrect versions for the backend modules (which are also organised a bit different since V1).

And you might also want to read the upgrade guides.

https://octobercms.com/support/article/rn-13

https://octobercms.com/support/article/rn-30

Good luck!

This will be many-step journey… :crazy_face:
Try going through this document and applying what’s relevant: Upgrading OctoberCMS v1→3 - Google Docs

Thank you very much @marco.grueter & @Eoler. I have decided to go with the route of creating a new project and then copying in my themes and custom plugins. This solution seems to have resolved all my issues. Thanks again