I’m using K3b 2.10.0.
I just burn a CD-RW medium with “Multisession Mode: Start Multisession” property, with some data.
And when I want to “Continue Multisession Project”, the “Session Import” dialog appears with the right session in it. But that session is not imported, so I cannot continue it.
(The same CD was used on the same CD/DVD device to do the same operation in openSuse 13.2, and that did work fine.)
It’s probably more important to know how k3b thinks your data disk is used, not what you’ve mounted.
As I described in my previous post, every disk burning app has an “Analyze” tool that reads what is already on the disk, and might verbosely describe what is possible… eg. data utilization, whether the disk is still considered multi-session or might have been closed.