Unable to import video - camcorder connected but no clips available for import

I have used FCPX without having this problem previously. Yesterday I connected my camcorder to my Mac with FCPX running. Rather than opening a dialogue window to import new clips, Photos window opened. I closed Photos and manually selected the Import menu. Media and XML options were in bold text, but no other options available. I selected the Import Media option and selected the camcorder's internal memory. No clips were displayed for selection/import.

I noticed that there was a FCPX update outstanding which included a patch to reinstate support for Panasonic video files (my camcorder is a Panasonic). I was also behind on O/S updates, so I installed all outstanding updates and then tried again.

When I opened FCPX I was prompted to update the video library files to make them compatible with the latest version - I did this, but one folder caused errors resulting in some clips not being processed, and therefore the folder still shows a yellow warning triangle.

I re-connected my camcorder, but again no clips were automatically detected. I manually selected the Import option, but again no clips were displayed.

A search on the web this morning suggested that options for Import and Playback (under preferences) might be out of sync, and this could be the cause of the problem. As far as I can see, these are all consistent, but having experimented a little with changing them, this hasn't resolved the problem.

I don't want to continue to make changes in the hope of resolving the problem - quite apart from the fact that I'll probably make things worse, I'd rather understand what's wrong so I can prevent it happening in the future. Apart from my attempts to correct this problem i haven't (knowingly) changed any other settings (that might have caused the problem). i have used the camcorder with FCPX before without any problems, and am not aware of any other factors that might have had an impact.

Please can anyone help?