Here are two attempts at rewriting the text:
Attempt 1:
Update software supporting FCPXML file extensions. Vegas Pro may not open FCPXML files if the version is old. Updated software versions implement support for newer formats. All file formats opened in previous Vegas Pro versions should open in current versions too.
To add FCPXML support, update the Info .plist with .fcpxml and .fcpxmld types per the Declare Document Type section of the Developing a Document-Based App sample code. The Xcode table shows Key, Type and Value columns. The Key column has nested Document Types under Information Property List.
The FCPXML format enables exchanging Final Cut Pro X project and event details with third-party apps not recognizing its documents and files. It uses XML elements to describe data exchanged between Final Cut Pro and third parties. You can transfer library, event, project and clip details between Final Cut Pro and unsupported devices and tools via XML documents.
Attempt 2:
Add FCPXML document support by updating the app’s Info .plist file. Include .fcpxml and .fcpxmld types as document types. Refer to the Document Type Declaration section of the Developing a Document-Based App sample code. The Xcode Information Property List table shows Key, Type and Value columns. The Key column has nested Document Types.
Update Vegas Pro. Old versions may not open FCPXML files. Developers add support for newer formats in updates. Previous Vegas Pro versions should still open all handled formats.
The FCPXML format enables sharing Final Cut Pro X details with unsupported third-parties. It uses XML elements to describe exchanged data. You can transfer library, event, project and clip details between Final Cut Pro and unrecognized tools and devices via XML documents.
Final Cut Pro X
DaVinci Resolve
Adobe Premiere Pro