Type error: Return value of Adrenth\Redirect\Classes\RedirectManager::redirectToCmsPage() must be of the type string, null returned return $controller->pageUrl($rule->getCmsPage(), $parameters);

Why do I get this error when i trying to open avatar page?

I have completely refactored the Gallery component today. Not sure if your issue is actually caused by the component, but update and give it a try.

On my own site I was getting an error in the gallery due to a corrupt avatar file. I could not even open the user record in the backend to edit them. I had to manually delete the file and remove the offending avatar record from the "system_files" table.

If you are seeing part of the gallery and then getting an error then try looking at the source of the page for last div tag in the source before the error. I have added a user id hint in the div id:

<div class="col-md-3 text-center" id="pic{{ person.id }}">

This should help you locate a possibly corrupt avatar file in the database. Thanks for reporting your issue.