FCPX has not recognised XAVC L for a while now, this has been documented by HDW with the problem ingesting from the PXW-X70 camcorder using XAVC HD, but this XQD problem is a lot more sinister.
This is an Apple problem, FCPX does not recognise XAVC L from the FS7 and will not eject your QXD card from the computer, your only option is to pull the card causing a problem with the Table of Contents (TOC). This is not an issue with XAVC I footage as it is recognised in FCPX.
Once you replace the XQD card into the FS7 you get the following message…
1. IMPORTANT : You must not have FCPX open at any time before ingest or after while the XQD card is in the card reader !
2. Making sure FCPX is not running, open Catalyst Prepare/Browse and import as normal.
3. Once you are finished importing eject your XQD card via Catalyst.
4. Now you can open FCPX.