It's been suggested you delete administrator/cache/autoload_psr4.php manually. The file will be re-created automatically.

Make sure the folder is writable though!

thank you vari much

I have the same issue. Did nothing deleted myself.

But mv the file administrator/cache/autoload_psr4.php to administrator/cache/autoload_psr4.something solved the issue for me.

Page is back.

See also https://docs.joomla.org/J4.x:Class_%22Joomla%5CPlugin%5CSystem%5CGuidedTours%5CExtension%5CGuidedTours%22_not_found

@thuebschmann did deleting the administrator/cache/autoload_psr4.php file help?

@thuebschmann did deleting the administrator/cache/autoload_psr4.php file help?

yes, for me it helped. but i just renamed the file to have it in case of more problems.

@thuebschmann did deleting the administrator/cache/autoload_psr4.php file help?

yes it helps i posted thank you 14 hours ago

I can reproduce the issue on new, clean installation on a clean 4.2-dev branch. When I use cli to update, the autoload_psr4.php has not changed after the update.

I don't know yet why this happens. The file should be deleted by the extract.php script here https://github.com/joomla/joomla-cms/blob/4.3-dev/administrator/components/com_joomlaupdate/extract.php#L1930-L1941 and also in the finalisation.php script here https://github.com/joomla/joomla-cms/blob/4.3-dev/administrator/components/com_joomlaupdate/finalisation.php#L74-L82 .

i can confirm this as well

@richard67 The code you are talking about is only executed when Joomla is updated using web updater. For CLI updater, that code is not executed, and that's the reason causing the error. Somehow, we will need to put that logic into UpdateCoreCommand

@richard67 The code you are talking about is only executed when Joomla is updated using web updater. For CLI updater, that code is not executed, and that's the reason causing the error. Somehow, we will need to put that logic into UpdateCoreCommand

@joomdonation Yes, I agree. Do you plan to work on that?

@richard67 I will see but could not promise because I haven't had any experience with console code. If someone is faster, please go head. I would say beside delete autoload_prs4.php, we should also include this block of code, too https://github.com/joomla/joomla-cms/blob/4.3-dev/administrator/components/com_joomlaupdate/extract.php#L1948-L1959

@richard67 I will see but could not promise because I haven't had any experience with console code. If someone is faster, please go head. I would say beside delete autoload_prs4.php, we should also include this block of code, too https://github.com/joomla/joomla-cms/blob/4.3-dev/administrator/components/com_joomlaupdate/extract.php#L1948-L1959

@joomdonation Also agreed. Unfortunately my time is very limited in the next two or three days, so I would be happy if you could work on it, and of course I would help if necessary.

the update log also needs to run on the cli update

checking other parts now

Please test the fix #40437