It’s not an issue, merely a deep debug log (this is why I used the trace log level).
The bundle tries to inject openHAB binding value in the script class, and for doing so, checks all class members (by their name). As the name (here, “logger”), doesn’t correspond to anything in the available openHAB bindings values, it logs a trace.
It could be null if the user doesn’t use the generated class “Items” as expected (for example, the user instantiate the Items class by himself instead of using the automatic injection provided by the bundle).
Therefore, I made this log suggesting the user to use the proper way.