I get this message during discussions "The following message could not be delivered to all recipient

Dear all,

This error message only started when I updated to version 6.1. In the middle
of a discussion to a single or group, Messenger simply doesn't deliver the
message. I then must retype the entire message, which soon becomes very
frustrating.

Thinking that there may be a conflict of the versions, I have looked to see
if I can uninstall the old version. However, I don't know if this is a
problem, and cannot find out how to do this either. Has anyone else
experienced this problem, and if so how was it corrected?