Upgraded to the most recent release for 28. I just got the same issue, so that didn't fix it. Here is more info that may help. I inserted a CD which was not recognised. I noticed up in the top menu bar of the ripping screen, the details of some other CD which I don't own, were displayed, so I tried to refresh the info. Didn't work, so I ejected the disk and re-inserted it. This time I got dual notifications, 1. the data from the disk was found (I could see it on the rip CD screen) BUT then 2. a pop-up window informed me that the data could not be found. I was offered two options, cancel or rip anyway. I am not sure what the correct answer is in this case. This time I pressed cancel. Somehow that deleted the CD info, so I ripped it as Unkown Artist etc. The next CD I put in (INXS) was recognised and ripped successfully. But the subsequent 2 CD's I tried to rip were locked on that INXS CD. They were not INXS. I recall now that in the past this may have been the trigger for this issue. I have selected cancel and rip anyway, and regardless of the selection, the next CD data gets locked. The only fix is to reboot.