Thank you Michael.
While this resolved the problems that I had (which I think should be seamless transition from FCPX to LPX without purchasing an app), the levels or transitions from FCPX were not transfered to LPX. Did I miss checking a preference between the process of FCPX – FCPXML – AAF – LPX?
Back in FCP7, I remember exporting OMF for ProTools and had all the levels and transitions transfered without having a problem…