There is a serious FCP bug whereby if Edit>Remove Effects or Edit>Remove Attributes is used on a retimed clip and adjacent non-retimed clips, it may cause the retimed clip to go black. Red "render bars" may appear which apparently are an undocumented corruption indicator. If the retime command and Remove Effects are repeated on the black clip, FCP may delete the clip from the timeline. This can happen to a single retimed clip or multiple clips at once. See attached.
If the user immediately recognizes the problem and does CMD+Z it can be recovered. However if FCP is re-launched or the machine rebooted, the timeline damage is locked in and unrecoverable. Copying the clips to another timeline or copying the project to another library or export/import of the project XML will not correct it. The source clip remains in the Event Browser but all connections to the retimed timeline clip (or clips) are severed. "Reveal in Browser" SHIFT+F on the black timeline clip will not find the source clip, and all timecode in the black clip has been wiped out. You can't match starting timecode and length and do an Edit/Replace to restore the damaged timeline clip range.
A before/after diff comparison of the project XML indicates FCP has lost track of the retimed clip duration and starting timecode. The XML probably reflects internal problems in the project-level SQL database tables containing clip attributes.
The problem apparently began in 10.5.3 and exists in 10.6.1 on both x86 and Apple Silicon.
The problem is somewhat inconsistent and more likely to happen with 4k clips of at least 60 sec duration. It happens with various codecs. It may not happen, then begin after FCP is re-launched. It happens on both rendered and unrendered clips. It may happen more frequently if all affected clips are trimmed to a shorter length in timeline before doing Edit>Remove Effects or Edit>Remove Attributes.
Various manifestations after Edit>Remove Effects on two or more clips including a retimed clip:
- Part of retimed clip becomes black
- All of retimed clip becomes black
- All black clip with red render bars
- 2nd retime command on black clip fills in thumbnails but red render bars remain and clip duration is wrong.
- 2nd Edit>Remove Effects on filled-in clip may delete the clip. If multiple retimed clips are in that state they may all be deleted from the timeline.
- FCP 10.6.1, M1 Max MacBook Pro 16, Monterey 12.1, Apple Pro Video Formats 2.2.2
- FCP 10.6.1, and FCP 10.5.3, iMac Pro, Big Sur 11.6.2, Apple Pro Video Formats 2.2.2
- FCP 10.5.3, 2017 iMac 27, Catalina 10.15.7, Apple Pro Video Formats 2.2.2
Problem still happens after:
- Resetting FCP preferences
- Removing and re-installing FCP
- Using a different MacOS user account
It does not happen on 10.5.2, so apparently it began in 10.5.3 which contained significant updates and fixes and required a library update.
I discussed this at length yesterday with Pro Apps escalation support, also filed the bug using the MacOS Feedback Assistant app.