My work has gone

[Hudson555x]

Sounds similar to this.
Providing a lot more detail along with screenshots will help tell the full story here.

Failed to open - MLT file

Your MLT file that you uploaded is not recoverable. [notepad++_2020-08-26_16-38-25] Read this: 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. [2020-08-25_13-55-36]