Hello,
Found a small issue in HMP, don't know in what release it is appeared but in all the latest it exists.
If a pupil or a coach is already present in the conference dcb_setcde function should fail when you try to make another conferee a pupil or a coach cause only one coach or pupil is allowed in one conference. It worked this way on physical boards and it partially works on HMP: setting the 2nd coach causes the dc_setcde error but setting the 2nd pupil does not.