Hi;
According to your advice, I redid the BDM as follows:
AdtA04: business variable (com.company.model1.AdtA04). which contains as attributes:
Id_msg: string,
pid: PID (another business variable) and
obx: OBX (another business variable of type list)
attached my .bos project?
https://drive.google.com/open?id=1ji7SbJvBlZWlc4jUzjwn6BvPF-uTX7Ln
I do not understand where is the problem?