Recorded file won't open.

[Confused]

I wanted to record 3 consecutive programs so I set the recording time accordingly. I trimmed out each program & saved them to a new file & then deleted the unwanted ends. 2 of the 3 recordings play OK but the 3rd says its an unsupported file format.

I restarted the machine to see if that made any difference, it didn't. I noted the amount of free space on machine then deleted this unplayable file. The amount of free space went up so the file must have been there all of the time.

I have had this happen before. Is there any fix for this if it happens again?

Thanks in advance