Random black clips when dragging project to another library

[Brett Sherman]

[Jiri Fiala] ” I was merely copying a project to a new library. “

The workaround is pretty simple then. Export an XML of the project. Import it into the new library.

[Joe Marler]

I again encountered this problem recently, investigated it to narrow the parameters and reported it to Apple Pro Apps support yesterday.

Symptoms: black media clips or red (missing proxy) clips when copying clips or projects to another library IF optimized/proxy files exist and IF you answer NO to the popup about copying optimized or proxy media. This is a common scenario when archiving a project and you don’t want/need optimized/proxy media copied to the destination archive library.

This only happens if using FCPX external storage as defined in the library inspector>Storage Locations>Modify Settings. Problem still happens if clips/project are copied to the destination library inside a “transfer event”.

Reveal in Finder on the black media clips in the destination library shows the regular media files which are playable. Transcode optimized/proxy is greyed out. May appear as “random” black clips, e.g, only certain clips in timeline are black. If so those are clips which had optimized media in the source library.

Workaround: delete generated optimized media or proxy files in destination library and rebuild, or if not needed (archive case), don’t rebuild them. The black clips will immediately fill in when the optimized media is “deleted”. Note there is no actual optimized media deleted in the destination library, since it was never there. It is a database error whereby FCPX thinks optimized media is there, tries to display it and it produces a black clip.

This only happens under the following conditions:

– Library storage must be external for source library when optimized/proxy media is generated. Destination library can use either internal or external storage. Media can be either copied to source library or imported with “leave files in place”.

Note in this case “external storage” does not necessarily mean an external drive or “in place” media. It only means a storage location external to the FCPX library has been defined in Storage Locations>Modify Settings, and afterward optimized/proxy media are created which places those files in that previously-designed storage location.

There is some variability which might at first appear to restrict problem to more specific storage cases, such as library and storage location on separate drives. Further testing shows it can happen even if source library, external storage location and destination library are all on the same drive, or even all on the same system drive. APFS vs HFS+ seems to make no difference.

To review: if you see black media or red proxy clips in a destination library after a cross-library copy of clips or projects, AND if during the copy you answered “no” to copy optimized/proxy media, then in that destination library try deleting the optimized or proxy media files. If the black clips immediately fill in, it is this problem. The red proxy clips are expected if you answered “no” to the copy dialog. However you cannot create new proxies in the destination library unless you delete the non-existent proxies, because the transcode dialog is greyed out.