Someone already faced this problem?
When someone sends a message to someone who is offline, the person receiving only reaches the first line.
Yes. It is already fixed in 2.7.5, which was a faast release to fix this issue https://igniterealtime.org/issues/browse/SPARK-1673
You have probably upgraded to Openfire 4.x, which has dropped support for older delayed messages extension, so Spark had to be updated.