HTTP ERROR 500 after upgrade to 4, propably PHP (8) issue [3.x]:

[hhentschel]

What happened?

Description

After upgrading to version 4 i get an HTTP ERROR 500. I can't even access the CP. I followed these and these steps.

i am on localhost and using Mamp pro. There i changed the PHP Version for this project to PHP 8.1.1. i also change this to the according php version in my .bash_profile

export PATH=/Applications/MAMP/bin/php/php8.1.10/bin/:$PATH alias phpmamp='/Applications/MAMP/bin/php/php8.1.1/bin/php'

when i revert the changes in composer.json to the 3.x. Craft Version and all the plugins to their older version, i get access to cp and the site works.

i think it has something to do with the php version. i looked at the logs, but i dont find any erros there.

Craft CMS version

3.7.48

PHP version

8.1.1

Operating system and version

Linux 4.19.0-17-amd64

Database type and version

MySQL 5.7.34

Image driver and version

Imagick 3.5.1 (ImageMagick 6.9.6-2)

Installed plugins and versions

CKEditor | 1.3.0 Expanded Singles - 1.2.0 Neo 2.13.15 Redactor 2.10.10 SEOmatic 3.4.36 Template Comments 1.2.0 Twigpack 1.2.17

[RetroChaos]

I had a similar issue. What do the logs in your craft/storage/logs say? That may help the actual Craft team diagnose the issue further.

Personally, what I did was try to upgrade Craft without any plugins first.

If that doesn't work, I exported my old db, did a fresh Craft install, installed the plugins I wanted, copied across my templates and assets, then restore my db via the command line.

[hhentschel]

Thanks. In the logs is nothing, what looks like an error.

I tried only update cms, without plugins, but then i get requirements errors.

ok, maybe i do that fresh install, i was hoping to avoid that.

[hhentschel]

i made a fresh craft 4 install.

what is the best practice for the next steps?

i copied the config project folder and tried a rebuild, but then i get this: Craft CMS is installed with schema version of 4.0.0.9 while 3.7.33 was expected.

when i try to import the db via phpmyadmin i get the error: Cannot add foreign key constraint

how do i restore the db via the command line?

[RetroChaos]

https://craftcms.com/docs/4.x/console-commands.html#db/restore

eg. php craft db/backup path/to/file.sq --drop-all-tables

I need to do one last test and document my steps properly, which I'm due to do tomorrow.

[hhentschel]

thanks a lot, would be very nice to read through your tests.

restoring the db via comman line, gives me the same error as importing: ERROR 1217 (23000) at line 2296: Cannot delete or update a parent row: a foreign key constraint fails

[RetroChaos]

If you cannot restore the backup anywhere then there seems to be an issue with your database at the point of backup. Are there any migrations pending?

I did this anyway:

1. Filesystem Backup
2. Database backup (eg. php craft db/backup backup-3x.sql)
3. Delete the entire install/folder
4. Re-install
5. Re-install plugins
6. Restore /template and any sub-directories in /web (be careful with index.php in the webroot, do not overwrite)
7. Restore database (eg. php craft db/restore backup-3x.sql). Don't drop any tables but clear the cache

[brandonkelly]

I’m not sure how a fresh install would make things any easier. Let’s just get to the bottom of the 500 response.

As a starting point, make sure Dev Mode is enabled in config/general.php:

'devMode' => true,

That should surface the actual error that is occurring. What is the error?

[brandonkelly]

Closing due to inactivity. Feel free to respond if you want to pick this back up though.

[SimonSoutas]

Yo, had the same problem, for anybody wondering: It was because I had something in my custom module which wasn't upgraded to php 8 properly 😅