I think i have seen this issue posted a lot. But i have never experienced this myself (nor at home, nor at work). My collegue havent complained about this either. But few months ago i have installed Spark to another coworker and everything was fine (except of a laziness and lockups of Spark). Few weeks ago this appeared the first time. She wasnt able to see her sent messages until the chat window was reopened. Same with the received messages. She's getting a popup, but nothing appears in opened chat window. Sometimes this would go away by itself. But the solution is to remove profile. First time i have deleted everything except the spark.properties. It helped for a week. Today i have deleted whole profile and started from scratch. Works fine so far.

I have a suspicion this can be caused by transcipt logs. Well, problem is appearing with messages showing up and Spark is showing a bit of recent history in a window by default. Could be related. Next time i will try to delete only transcripts.

Another thing is maybe windows updates. First two times i believe happened just after the recent updates.

Logs are empty (it's just a week old profile).

Spark 2.5.8

Windows XP SP2