10bit prores 422 in Final Cut Pro X - Help urgently

How are you converting these Raw clips?

I am thinking that Sierra may be the problem.

You probably are running FCP X 10.3.4. Both the OS and FCP X version are a few years old.

Do the clips play correctly (i.e. not red) in Quicktime Player?

What is your mac model?

Does it support Catalina?

Unless your mac is too old, I think you should upgrade your OS and FCP X - to the current versions, if possible.

I understand that compatibility with the software you depend on is a genuine concern.

I would suggest testing the waters by installing Catalina on an external drive.

This would not only let you keep your present system, but also gradually test to see if your other software works without fully commiting to the upgrade.

(In any case, one should NEVER do such a major upgrade without a full working backup - this should include BOTH an up to date Time Machine, and a full bootable clone of the system, on separate drives)

The current version is 2.1..1. I don’t think you can update it with that OS.

I presume you’ve disabled auto update. In Sierra updates are all in the App Store. I’ll have to check but the pro video format should be in System Info under Software. It may be different in your OS.

Apple Sign->About this mac

System Report->Software->Installations

What version of Pro Video Formats are you using?