Change role of RETIRED user in Skype group chat

Question

In existing Skype group chat, i cannot add one specific user.

When i enter /showmembers , it gives:

andrew USER

bobby ADMIN

catrin USER

diana RETIRED

in this case: i'm bobby the admin and diana is our user in question. So:

• i cannot add her to chat - i get: diana can't be added until they accept your contact request., and she gets: You have been removed from this conversation and will not be able to join.
• i cannot /set role USER - diana can't be added until they accept your contact request.
• i cannot remove her with /kick - nothing happens
• i cannot ban this user with /kickban - i see the list of commands, so probably this is deprecated
• giving the link to join chat also does not work, even with options JOINING_ENABLED

version of skype is 6.21.0.104 Windows 7.

Reading on the internet, i suspect that Skype/Microsoft might have broken the group chats. Yet i hope this is not the case, and my problem can be solved.

Question: How to add a user who is RETIRED to the group chat ? or change his role to USER ?