No clue where to start

So, the developer just left, leave a big mess behind.
The log in screen is in blank, just with the header of SUITECRM logo and the purple band… nothing else.

I would like to understand a way to run this again and can access the system and Admin, to try check what he did or did not… but, I´m unable to log in.

Any way to put this to work again?

Thanks in advance, im in kind of a hurry because the state he left me with.

You can look into the suitecrm.log to see what is failing
Also you can inspect the login screen and look in the console what the issue is

check out suitecrm.log file on the server/crm root and ensure that the database is still up and has correct credentials. If you have any backups, you can start fresh through install process.

It seems its related with PHP. I do go backwards to PHP 7.4 and get the login screen with a lot of errors in the login screen, but in PHP 8 I did not get even the screen.

The errors are kinf of this:

[Notice] Undefined index: LOGIN_ERROR occurred in /home/user/^750^750EB194%%Login.custom.tpl.php on line 135 [2023-06-22 20:46:47] display_stack_trace caller, file: /home/ser/ line#: 3826

And there are a lot of those, all over the system, even when you log in.
Just the ADMIN page is viewed without errors.

Not sure what to do. Any clue?

Disable display_errors in your php.ini.