what is the blocking message ?

No message,

The status field is missing :
 

Yes, 
Periodic meetings don't have status.
So right, they should have closed checkbox clickable (not readonly)

So it's a true bug, or is it just in my instance of projector ?

Hi !

No it's not a bug.
In fact, your basic recurring meeting is an envelope that contains the meetings. So this envelope has no state.

The CLOS checkbox is not available due to the behavior of your meeting type.

You must modify this behavior by unchecking "lock closed" so that the states of the meetings included in this envelope do not define the closure of this envelope.

Hi,

In fact it is an issue as checkbox should not be readonly on periodic meeting, whatever the definition on the type, as periodic meeting do not have status.
This will be fixed on next patch.

Thank you, it works.

Yes it would be great to be able to close it or autoclose it when all meeting are closed.

Regards,