The message is placed wrongly if I take left message (from the menu) and I am trying to connect it to the coregion in the example. The mistake is shown only if the connection point for the message is marked as whole coregion.
The problem is that in visio connection of a message to "whole coregion object" is allowed - not only to the dashed lines.
Similar problem we have with all objects in HMSC.
I began working on this ticket today.
Bug is already found and fixed, please, check it and possibly close this bug.
The bug is fixed, but we don't know why the patch is not working when user uses previously created diagram or creates new diagram by "recently used tamplate".