Codeception gives PHPUnit framework exception


I’m using Codeception with CakePHP 3.5, and has written a few testing steps. But when executing them, it gives me an error when there should be no error as far as I can see. The first few steps works fine, but when I get to the step to click on a button, I get the error “PHPUnit framework exception: array to string conversion”.

I’m using the codeception code:
$I->click([‘button’ => [‘title’ => ‘Delete testtest, tt’]]);

Trying to click on the element:
<button class="btn btn-primary btn-xs delete-namestring" title="Delete testtest, tt" id="20867"><span class="glyphicon glyphicon-trash"></span> Delete</button>

Clicking on it manually works fine.