TYPO3 Core

When I'm using the Page module and I click on the pencil of the third (or higher) content item, i get this message: "Sorry, you didn't have proper permissions to perform this change."

Note: no problems in the context menu->edit or List module.

The error is caused by typo3/sysext/backend/Classes/View/PageLayoutView.php line 1313:

$params = '&edit[tt_content][' . $this->tt_contentData['nextThree'][$row['uid']] . ']=edit';

It appears that $this->tt_contentData['nextThree'] is empty at the third content item. An easy fix would be to replace $this->tt_contentData['nextThree'][$row['uid']] with $row['uid']

Out of curiosity, what is the function of this 'nextThree'?