With the zs-client.phar file that is provided with this module (as of 2017-05-01), the --logo parameter is mandatory when doing some actions, like defining an application and the error message is not that clear (it only states that a file doesn't exist, but it doesn't say which). However, with the .phar provided with Zend Server 9.1, this parameter is not required. This is just a heads-up to help people hitting the same problem. It should be solved in a future version of this module, which will push the .phar only for versions of ZS that don't provide it and use zs-client.sh script to make sure the latest .phar is used.
With the zs-client.phar file that is provided with this module (as of 2017-05-01), the --logo parameter is mandatory when doing some actions, like defining an application and the error message is not that clear (it only states that a file doesn't exist, but it doesn't say which). However, with the .phar provided with Zend Server 9.1, this parameter is not required. This is just a heads-up to help people hitting the same problem. It should be solved in a future version of this module, which will push the .phar only for versions of ZS that don't provide it and use zs-client.sh script to make sure the latest .phar is used.