Failing to read some files when run on a large number of files

**Describe the bug**
When I run FFmpeg in a loop over a large number of files, some files are giving a read error.

"Error: File could not be read! Code=0"

The same files can be read if running as part of a smaller number of files. Some of them do take some time to read so there may be issues with some of the files, but they can be read.

I tried doing a try-catch loop to rerun the files but it seem to just instantly fail them on retry. If I rerun the app after it has finished, without reloading the page. to go over the files that failed, it will instantly fail to read them. If I refresh the page and run it on just some of the failed files it reads them.

**To Reproduce**
You can run my app over a large number(> 100) of video files to see if you get the same behaviour.

https://github.com/1Syler/nextpvr-importer

**Expected behavior**
I expect it to read the same files all of the time, not some of the time. A way to retry that doesn't instantly fail.

**Desktop (please complete the following information):**
- Linux Mint 20
- Chrome
- Version 87.0.4280.141 (Official Build) (64-bit)