Write metadata to MP4

[frankdarwin]

I have 2 MP4 files in which metadata should be written (see attachment).

But the metadata is not written back.
What is the problem?

[Mario]

You are not providing  a minimum of information.
This screen shot tells me nothing.

But the metadata is not written back.

What does this mean? Does clicking the pen do nothing? Does IMatch display an error message?
Did you check the ExifTool output panel for error messages and warnings. The Output Panel
Did you check the IMatch log file for errors and warnings (right after you clicked the pen), open the log and search for W> and E>.

[frankdarwin]

The problem is fixed.
After reading the log file, I was able to identify the problem.
The two files were read-only. I had overlooked that in the file window.
Thanks!

[Mario]

Me too. But the first file in your screen shot has no read-only shield, and the second is barely visible.