What happened?

When accessing Matomo dashboards or loading the TagManager module, the following error appears in the log:
ERROR Piwik\ExceptionHandler [...] Uncaught exception: /core/FrontController.php(502): The plugin ActivityLog is not enabled. You can activate the plugin on Settings > Plugins page in Matomo. [Query: ?action=index&module=ActivityLog, CLI mode: 0]

What should happen?

Error appears regularly in matomo.log.

ActivityLog plugin was never installed (paid version).

Dashboard or TagManager functions otherwise run normally.

How can this be reproduced?

The error is caused by the TagManager plugin.

In plugins/TagManager/Activity/BaseActivity.php, there is the following line:

use Piwik\Plugins\ActivityLog\Activity\Activity;

Since the ActivityLog plugin is not installed, PHP tries to find the namespace when loading this class, fails, and throws the error.

Other plugins or dashboards are not affected.

Matomo version

5.5.0

PHP version

8.3

Server operating system

No response

What browsers are you seeing the problem on?

No response

Computer operating system

No response

Relevant log output

Validations

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• Check that there isn't already an issue that reports the same bug to avoid creating duplicates.
• The provided steps to reproduce is a minimal reproducible of the Bug.