Hi mluecke,

I confirm you that the Ligtstreamer 5.1.1 Moderato Edition can be used for free even in production environments and does not require any license key.
The error messages you post here are quite strange since they seem to refer to the old version 4.x that indeed requires a license key.

Please can you look for message like this "Lightstreamer Server x.x.x build xxxx" in the server log in order to ascertain the version in use?

Thank you,
Giuseppe