Okay, provided, plugin available.
When trying to activate -> ADMIN+MANAGE_PLUGINS_SERVER_INVALID_RESPONCE_ERROR_MESSAGE
Deleted, and tried again to upload, now not asking for FTP credentials, plugin available.
Tried to activate, same error message.
Okay, after a quick debug: this error comes up if external licensing server not available.
Erm, i want to use this plugin internally in our company, so there is no connection possible to the outside...