I'm new to Enterprise Architect. I created some sequence diagrams using enterprise architecture. However, while I exported it to another EA, the messages were all gone and I could only get the lifelines of each classes.
Please advice.
The solution is to use lifelines from the toolbox and classifying them rather than dropping classes as link. As long as you just use a single repository all is fine. But once you export/import via XMI (also when using version control) your messages will be gone. This is described somewhere in the help, though hard to find.
When dropping classes use Lifeline:
Or the toolbox element: following Ctrl-L to classify.
Actually using classes in SDs is plain wrong. A class does not send messages but instances do. Unfortunately EA does not prevent users from dropping classes as link on SDs. You only recognize your fault once you use XMI.