The way registering a wizard in TCA has changed in 6.2. Please set module[name]=module_name instead of using script=path/to/script.php in your TCA. The possibility to register wizards this way will be removed in TYPO3 CMS 7.
As Kitodo.Publication should be already compatible with TYPO3 7.6, this is a bug.
From deprecation.log:
The way registering a wizard in TCA has changed in 6.2. Please set module[name]=module_name instead of using script=path/to/script.php in your TCA. The possibility to register wizards this way will be removed in TYPO3 CMS 7.
As Kitodo.Publication should be already compatible with TYPO3 7.6, this is a bug.