Failed to open - MLT file

[Hudson555x]

Your MLT file that you uploaded is not recoverable.

Read this:

"Failed to open" error message after updating

This file is corrupt and it has nothing to do with the upgrade. The only way to recover is if you have a backup. You can read more about it by searching here on “NUL” or the web in general on “windows file null character” to find something like this. As far as we can tell this is not due to a bug in Shotcut but something in the way Windows does caching or hardware. Shotcut first writes a temporary file, verifies it valid XML, and then renames it to the name you provided.

@HeresALook

but I’d like to know what went wrong and how I can prevent this from happening

As far as the file getting corrupted, there is nothing you could have done differently.

To protect yourself in the future, start using Save As. Save the file to two or three different file names as a backup.