Same issue as before

Have the same issue as before ....
Tries to upgrade to 10.1.2 and get the error. Deleting the autoload.psr doesn't help, deleting the sourcerer doesn't help.
Can install 10.1.1 but not 10.1.2.

//Dennis

Ett fel har inträffat

0 Failed opening required '/data/f/9/f93134be-1f5f-4335-8028-ffe48300a2c6/rojteatern.nu/public_html/administrator/cache/autoload_psr4.php' (include_path='.:/usr/share/php')

Call stack
# Function Location
1 () JROOT/libraries/namespacemap.php:104
2 JNamespacePsr4Map->load() JROOT/libraries/src/Application/ExtensionNamespaceMapper.php:34
3 Joomla\CMS\Application\CMSApplication->createExtensionNamespaceMap() JROOT/tmp/install_665ef896c18e2/packages/j4/pkg_regularlabs/script.install.php:71
4 pkg_regularlabsInstallerScript::recreateNamespaceMap() JROOT/tmp/install_665ef896c18e2/packages/j4/pkg_regularlabs/script.install.php:35
5 pkg_regularlabsInstallerScript->postflight()
6 call_user_func_array() JROOT/libraries/src/Installer/LegacyInstallerScript.php:158
7 Joomla\CMS\Installer\LegacyInstallerScript->__call() JROOT/libraries/src/Installer/LegacyInstallerScript.php:187
8 Joomla\CMS\Installer\LegacyInstallerScript->callOnScript() JROOT/libraries/src/Installer/LegacyInstallerScript.php:113
9 Joomla\CMS\Installer\LegacyInstallerScript->postflight() JROOT/libraries/src/Installer/Adapter/PackageAdapter.php:599
10 Joomla\CMS\Installer\Adapter\PackageAdapter->triggerManifestScript() JROOT/libraries/src/Installer/InstallerAdapter.php:802
11 Joomla\CMS\Installer\InstallerAdapter->install() JROOT/libraries/src/Installer/Installer.php:647
12 Joomla\CMS\Installer\Installer->install() JROOT/libraries/src/Installer/Adapter/PackageAdapter.php:157
13 Joomla\CMS\Installer\Adapter\PackageAdapter->copyBaseFiles() JROOT/libraries/src/Installer/InstallerAdapter.php:740
14 Joomla\CMS\Installer\InstallerAdapter->install() JROOT/libraries/src/Installer/InstallerAdapter.php:1261
15 Joomla\CMS\Installer\InstallerAdapter->update() JROOT/libraries/src/Installer/Installer.php:833
16 Joomla\CMS\Installer\Installer->update() JROOT/administrator/components/com_installer/src/Model/UpdateModel.php:453
17 Joomla\Component\Installer\Administrator\Model\UpdateModel->install() JROOT/administrator/components/com_installer/src/Model/UpdateModel.php:353
18 Joomla\Component\Installer\Administrator\Model\UpdateModel->update() JROOT/administrator/components/com_installer/src/Controller/UpdateController.php:58
19 Joomla\Component\Installer\Administrator\Controller\UpdateController->update() JROOT/libraries/src/MVC/Controller/BaseController.php:693
20 Joomla\CMS\MVC\Controller\BaseController->execute() JROOT/libraries/src/Dispatcher/ComponentDispatcher.php:143
21 Joomla\CMS\Dispatcher\ComponentDispatcher->dispatch() JROOT/libraries/src/Component/ComponentHelper.php:361
22 Joomla\CMS\Component\ComponentHelper::renderComponent() JROOT/libraries/src/Application/AdministratorApplication.php:143
23 Joomla\CMS\Application\AdministratorApplication->dispatch() JROOT/libraries/src/Application/AdministratorApplication.php:186
24 Joomla\CMS\Application\AdministratorApplication->doExecute() JROOT/libraries/src/Application/CMSApplication.php:293
25 Joomla\CMS\Application\CMSApplication->execute() JROOT/administrator/includes/app.php:61
26 require_once()

I've asked the web-hosting support (as suggested by joomla support) and they can't find any issues.

"My hosting service had the permissions checked:

0755 to the directory "cache" is the correct one, and 0644 to the file is correct.

Owner and group (user:group) is correct and is set to be the user that runs the PHP-process at the webbsite."

And the sourcerer is the only plugin that I've got this problem with.

//Dennis