Sure, I know you can compress it during output from FCPX. I was only suggesting a straight export from FCPX to make sure that worked properly first. I find that limiting the number of variables helps when you're diagnosing the cause of an error like this.
For what it's worth, if you're getting errors when exporting a master file I would suggest attempting to export smaller ranges of your project. I have found that there is usually a shot that is causing problems and that is the best way to ID the offender.
I really don’t Understand, I can export to antoher YouTube acount from fcpx. Not the one I need to use. I went on YouTube /google setting to be sure fcpx is allowed to access to the account. Everything looks allright but I still can’t export...
Regis wrote: I really don’t Understand, I can export to antoher YouTube acount from fcpx. Not the one I need to use. I went on YouTube /google setting to be sure fcpx is allowed to access to the account. Everything looks allright but I still can’t export...
Did you delete the Youtube destination in FCP X and create a new one?
Error -50 is a general error for moving or copying files so your issue is most likely a problem with either the files themselves being corrupted or location change or location data. The fact that you can export other project(s) to YouTube basically confirms this.
As Jarrod says, try exporting 1/2 of the project, then if you still have problem, divide in half again till you find the section that is giving you the problem. Sometimes while doing this, you may get a pop-up window with more info.
You can also see if "Console" will give you needed info. Console is in your Utilities folder, it keeps track of computer processes. Your error log will show up there and most likely identify the clip causing problems. However, console logs have a bit of learning curve to them.
Error -50 can be from moving files from drive to drive, improper importing of files, renaming files, etc… but somewhere along the line, you have one or more clips, or possibly a plug-in that is misbehaving. If you have included photos in your project, this can also lead to problems.