damaged event

Hello,
I have a damaged Library. I guess it comes from a damaged Event that I cannot copy to another new and clean Library. When I open the Library bundle containing this Event, I can see that the transcoded media folder of the Event shows two aliases for the same clip, one named xxx.mov, the other named xxx (fcp1).mov. Everytime I select this Event in the Library, FCP crashes. I cannot scroll this event normally, it crashes also. All kind of operations on the Library lead to a crash.
Thanks for your help.

(fcp1) means it's a second clip that has the exact same name as a previous clip. This is how FCP handles multiple clips with the same name. That's probably not the issue. Your issue will probably be in the FCP library's database, something got corrupted.

One thing to try, is deleting all of the render files. I'd use Final Cut Library Manager and go one step further. I'd use it to delete all render, optimization, and analysis files. Then launch FCP holding both Opt & Cmd keys together to delete FCP's preference files.

If that doesn't help, look in your backup folder (in your Movies folder) and try opening a previous version.

Thank you Ben for your answer. I've done what you suggested. I also removed the CurrentVersion.flexolibrary. That doesn't work either.
Now there is a complex history to that problem. Luckily, I’m only in the process of viewing the dailies. No editing work has been done yet on the approximately 7 TB of clips (about 2,200 of them).
Some time ago I imported the mxf original shoot. Clips were normally converted to .mov files with proxies. During that process, I had a couple of problems with my RAID array (DROBO). The DROBO had to reconstruct the whole thing. It was a purely mechanical problem of disk insertion and I was sole responsible for it, not the DROBO (unless you take into consideration the fact that a DROBO drive does not secure disks correctly). Then everything became alright it seemed. All clips were imported and their proxies were correctly made so I was able to describe all of the clips and give them keywords. Fine.
Some time ago again, after FCP and OSX were updated to their new version, I couldn’t open my Library. With some help I could finally do it but it went awry again. And I’ve tried since then to recover it.
One Event seems damaged. I cannot select it in FCP. If I do so the app crashes. I cannot open the keywords command, it crashes. However, I can watch the clips and see all informations about them.
I wonder if the (fcp1) addition (that goes with a copy of ALL proxy aliases in the Transcoded Media folder of the FCP bundle) is not related to the first crash.
I have more to say but would prefer to wait for your questions.
Thank you

On more thing: backups crash all the same.

Well, in one word I'm just anxious to retrieve notes and keywords I added to the clips. There's nothing else that has been done on the project yet.

Helped a friend that had this problem a few years back. Had him send me the library (all the assets were elsewhere on his drives). Opened it with all sorts of missing file warnings but that didn't matter. I saved it as a completely new library and sent it back to him. The new library opened just fine and located the files without a problem. Never understood what the problem was only that whatever I did worked out the mysterious kink. (One thing I do is export an XML file tagged with date & time exported whenever I close the project, because you never know...)

Thanks for your message. But I think I found a solution. Is it only temporary until the problem starts again, I don't know. As Tom Wolsky answered on March 30 to a post about an Event that didn't show, one needs to remove the Currentversion.flexolibrary located in the Library bundle (if you control click on the bundle you can open it). Then after you close the Library and quit FCP (without crashing meanwhile), the file is automatically reinstalled and updated. I have the impression it fixes this kind of issues. Now my Library works fine and I can scroll the Event normally. To be followed…

Of course, you have to remove this file before you open FCP.

Yep, database corruption... They are in fact very rare, but can happen.

Stephane Breton wrote: ...I’m only in the process of viewing the dailies. No editing work has been done yet on the approximately 7 TB of clips (about 2,200 of them)....I had a couple of problems with my RAID array (DROBO). The DROBO had to reconstruct the whole thing....All clips were imported and their proxies were correctly made so I was able to describe all of the clips and give them keywords. Fine.
Some time ago again, after FCP and OSX were updated to their new version, I couldn’t open my Library. With some help I could finally do it but it went awry again. And I’ve tried since then to recover it.
One Event seems damaged. I cannot select it in FCP. If I do so the app crashes...

Stephane, sorry about the problems. Normally FCP has excellent data integrity and library corruption is rare. I have used FCP libraries on a NAS but in general I recommend keeping your library locally on your machine (ideally on a fast SSD formatted as APFS or MacOS Extended Journaled (aka HFS+), not on the NAS server. Media files are OK on the NAS. FCP emits a high rate of small random IOs to the library which can conflict (performance wise) with the sequential reads used for media, if on mechanical drives. Also APFS and HFS+ are transactional file systems and tend to be resilient to crashes, which is important for the library since that contains all your edits.

An exception to the above might be if using a Lumaforge NAS, which is highly optimized for FCP.

As an additional backup you may wish to periodically (e.g, daily) export and save an XML of the library and/or event and project. This just takes a few seconds, and the files are very small. If done once per day, you have an external snapshot of the library metadata each day in XML format, which is different from the internal SQL format used inside the library.

My suggestion is use a "lean library" where proxies and cache are external to the library. This keeps the library small and enables easy duplication of the library in Finder as an additional backup method. I usually keep the cache on the same dedicated SSD as the library. You can designate those storage locations using the library inspector>Storage Locations>Modify Settings.

If you have already created proxies inside the library, as of 10.4.9 we have proxy relink. In theory you can use Finder to move the proxies from within the library bundle to an external folder, then use Files>Relink Files>Proxy Media and relink to the new proxy location. I've only tested that on small data sets; always exercise caution and have backups when directly manipulating items inside the library.

Here are some previous posts regarding organizing media in FCP on large documentary projects:

www.fcp.co/forum/4-final-cut-pro-x-fcpx/...gement-system#109082

https://www.fcp.co/forum/4-final-cut-pro-x-fcpx/33719-remote-documentary-workflow-suggestions#108930

Ripple Training's review of new FCP proxy features: 

Here are some tips on using FCP from a Hollywood Avid editor:  www.youtube.com/channel/UCZEWB-9BQ2DW-gwBlJJaWNg

Many thanks Joema. Good advices. Now everything is alright.
All the best,