cant update / error when update at backend

I try to update my joomla 5 with Jux portfolio 2.4.3. I get the message:

Warnung
JInstaller: :Install: Die XML-Installationsdatei konnte nicht gefunden werden.
×
danger
Die Manifest-Datei konnte nicht gefunden werden.

It means:
Warning
JInstaller: :Install: The XML installation file could not be found.

×
Danger
The manifest file could not be found.

I cant find any information or special rules to update it at the documentary. It means update by upload extention regular at the backend.

Did you know what was the problem here?