Can not install eventon plugin

If you understand german here is the message:

Installiere Plugin aus Datei: codecanyon-1211017-eventon-wordpress-event-calendar-plugin (1).zip
Entpacken des Pakets …

Das Plugin wird installiert …

Das Paket konnte nicht installiert werden. Es wurden keine funktionsfähigen Plugins gefunden.

Die Plugininstallation ist fehlgeschlagen.

Zurück zur Plugin-Installation

i did the installation often but always with the same result. On other web for other client i did it without any problems. Can you help.

Thank you in advance

If you are installing it more than once that could be the issue as you need 1 purchase/license per website/installation

I have 2 installations and two licences. But since i deleted one installation to reinstall it i cant install it any more. the information i have got in german translated in english: The package could not be installed. No working plugins were found.
The plugin installation failed.

Please help

Assuming there are no restrictions on removal and re-installation then it sounds like you may be installing the wrong folder but if it works on another site it can’t be that so I would suggest contacting the author.

oh wonder, i tried it this morning again SUCCESS! I dont know why.

May you help me in other case?
i like to show only month with events. How can i do that?

That’s very specific to the plugin - you need to ask the author