Using Off The Record (OTR) for the first time we had an initial problem getting this feature to work. The symptom was that an OTR connection was attempted, it connected then almost immediately disconnected after less that 10 seconds. What appeared to help and make the OTR connection stable for more than a brief period was to add the stunFallbackHost=<whatEverRelevantServer> to the Spark.properties file, that and restart Spark.
Is this stunFallbackHost setting relevant and necessary to making the OTR feature work ?
There seems to be some part of the OTR connection management that does not clear out previous OTR connection attempts, at one point the chat window was showing two spinning "trying to connect" OTR notices and 4 "connected" OTR notices.
There still appears to be some issues with file transfer, the file transfer progress bar stalls and no confirmation notification is displayed even though the file is sometimes successfully transferred. Sometimes the file does not transfer at all. However sometimes the transfer just works although there are more failures than successes. A common element is that the connected users all are using some personal VPN to the OpenFire Server as a result their PC will have at least two IP addresses.
In our department because the members are spread over different locations and time zones we regularly use a chat room for group communication. When in the chat room and you start a one to one chat with another chat room member by double click on their chat room presence the personal chat does not show the usual icons to allow screen capture etc. When you hover over the Chat window tabs the Jabber ID is different, presumably this is why the Icons are not visible because Spark has not identified that the selected contact from the chat room is possibly an established roster contact or a co-member of a group.
A possibly interesting new feature request would be file transfer between MUC room members.